1. A waterproof and drainage construction method for backfilling and laying underground cables and PE (polyethylene) guide pipes is characterized by comprising the following steps:

step S1: carrying out field exploration according to the underground structure construction design drawing;

step S2: carrying out underground main structure construction;

step S3: paving a backfill soil layer (10) on the underground main body structure, and forming a herringbone slope surface structure with a high middle part and two low sides under the laying trend of the high-voltage cable and the PE guide pipe (2);

step S4: constructing a waterproof isolation box body on a backfill soil layer (10) of a herringbone slope structure, wherein the waterproof isolation box body is of the herringbone slope structure with a high middle part and two low sides, two sides of the waterproof isolation box body extend out of a foundation pit (1), and a high-voltage cable and a PE (polyethylene) pipe (2) are installed in the waterproof isolation box body and are laid in a herringbone shape;

step S5: and continuing the paving construction of the backfill soil layer (10) until the backfill reaches the top surface of the foundation pit (1).

2. The waterproof and drainage construction method of underground cable and PE pipe backfill laying according to claim 1, wherein said step S2 includes the following steps:

step S21: constructing a fender post (3) in the foundation pit (1) except for the design position of the section affected by the positions of the high-voltage cable and the PE guide pipe (2);

step S22: after the concrete strength of the fender post (3) reaches the design requirement, constructing a top beam (4) and a retaining wall (5);

step S23: carrying out concrete support beam construction;

step S24: carrying out suspension and protection construction on the high-voltage cable and the PE guide pipe (2);

step S25: after the excavation condition of the foundation pit (1) is checked and accepted, constructing the underground main body (6);

step S26: after the strength of the top plate concrete of the underground main body (6) reaches the design requirement, the high-voltage cable and the PE guide pipe (2) are removed for suspension and protection construction;

step S27: erecting an H-shaped steel pipe supporting platform on the top surface of a top plate of the underground main body (6) to support the bottoms of the high-voltage cable and the PE guide pipe (2) in a jacking mode, and cutting and moving out the concrete supporting beam;

step S28: and (3) constructing a top plate coating waterproof layer (7), a root resistance layer (8) and a fine aggregate concrete waterproof protective layer (9) on the top surface of the underground main body (6).

3. The waterproof and drainage construction method of underground cable and PE pipe backfill laying according to claim 2, wherein said step S3 includes the following steps:

step S31: after the concrete strength of the fine aggregate concrete waterproof protective layer (9) meets the design requirement, paving a backfill soil layer (10) on the fine aggregate concrete waterproof protective layer (9);

step S32: when a backfill soil layer (10) is paved and constructed to the top surface of the crown beam (4) and the bottom of the high-voltage cable and the PE guide pipe (2), breaking a retaining wall (5) in a backfill paving construction section to the top surface of the crown beam (4), and exposing the high-voltage cable and the PE guide pipe (2);

step S33: arranging herringbone slopes at the central line position of a backfill soil layer (10) laid under the laying direction of the high-voltage cable and the PE guide pipe (2) to the two sides of the foundation pit (1) respectively, calculating and measuring the elevation at the central line position of the foundation pit (1) and the elevations at the top outer edges of the top beams (4) at the two sides, and enabling the elevation at the central line position of the foundation pit (1) to be higher than the elevations at the top outer edges of the top beams (4) at the two sides so as to form a herringbone slope structure with the middle height and the two sides low.

4. The method for constructing water and water repellent structure by backfilling underground cables and PE pipes according to claim 3, further comprising the following steps between the step S3 and the step S4:

step S34: and pouring a concrete cushion (11) on the top surfaces of the backfill soil layer (10) and the crown beam (4), and brushing two waterproof coatings on the surface of the concrete cushion (11) to form a waterproof coating (12).

5. The waterproof and drainage construction method of underground cable and PE conduit backfill laying according to claim 4, wherein said step S4 includes the following steps:

step S41: laying a layer of waterproof coiled material on the surface of the waterproof coating (12) in the backfilling laying construction section to form a waterproof isolation layer (13), and respectively extending the waterproof coiled material to the top outer edges of the crown beams (4) at two sides by 500mm during laying;

step S42: arranging a row of locators (14) at intervals of 500mm from the beam tops of the crown beams (4) on two sides to the position of the central line in the foundation pit (1) on a waterproof isolation layer (13) in a backfilling laying construction section, wherein each row of locators (14) comprises 4 abutted locators (14), and the arrangement direction of each row of locators (14) is vertical to the laying direction of the high-voltage cable and the PE conduit (2);

step S43: installing the high-voltage cable and the PE guide pipe (2) on the positioner (14) and laying in a herringbone manner, and dismantling the H-shaped steel pipe supporting platform below the high-voltage cable and the PE guide pipe (2);

step S44: in the backfill laying construction section, along the laying direction of the high-voltage cable and the PE conduit (2), the two sides of the waterproof coiled material are turned over by 90 degrees from the outer side to the inner side along the bottom of the positioner (14) to form a structureA character shape;

step S45: filling the periphery of the high-voltage cable and the PE guide pipe (2) to form a drainage filling layer (15);

step S46: the waterproof coiled material is turned over from the outer side to the inner side along the top of the positioner (14) for 90 degrees to form a square shape, and the waterproof coiled material wraps the high-voltage cable, the PE guide pipe (2), the positioner (14) and the drainage filling layer (15) to form a waterproof isolation box body with a herringbone slope surface structure, wherein the middle of the waterproof isolation box body is high, and the two sides of the waterproof isolation box body are low.

6. The method for waterproof and drainage construction of underground cable and PE conduit backfill laying according to claim 5, wherein the step S45 specifically comprises the following steps:

step S451: at the bottom of the high-voltage cable and the PE conduit (2)Pebbles with the thickness of 50mm are filled in a cavity between the character-shaped waterproof rolls to form a water permeable layer;

step S452: and (3) filling a dense fine sand layer with the thickness of 70mm on the surface of the permeable layer to support the bottom of the high-voltage cable and the PE conduit (2), and continuously filling the fine sand layer to the top surface of the positioner (14) to completely cover the high-voltage cable and the PE conduit (2).

7. The method for water and water drainage construction of underground cable and PE conduit backfill laying according to claim 5, wherein a U-shaped groove (141) is formed on the top surface of the positioner (14), the high-voltage cable and the PE conduit (2) are installed in the U-shaped groove (141), and at least one water through hole (142) is formed on the bottom surface of the positioner (14).

8. The method for constructing water-proof and drainage in underground cable and PE conduit backfill laying according to claim 7, wherein the distance from the bottom surface of the U-shaped groove (141) to the bottom surface of the positioner (14) is 100mm to 150 mm.

9. The method for constructing water and water repellent structure by backfilling underground cables and PE pipes according to claim 1, further comprising the following steps between the step S4 and the step S5:

step 45 a: the method comprises the steps of continuously backfilling soil to the top surfaces of waterproof isolation box bodies on two outer sides of the waterproof isolation box bodies in a backfilling laying construction section, paving sand cushion layers (17) on the top surfaces of the waterproof isolation box bodies and the surfaces of backfill soil layers (10), wherein the width of each sand cushion layer (17) exceeds 500mm of each side outside the waterproof isolation box bodies, constructing reinforced concrete protection plates (18) with herringbone slope surface structures, wherein the middle of each reinforced concrete protection plate (18) is high and the two sides of each sand cushion layer are low, the width of each reinforced concrete protection plate (18) exceeds 1000mm of each side outside the waterproof isolation box bodies, and the longitudinal length of each sand cushion layer (17) and each reinforced concrete protection plate (18) exceeds 500mm of each top outer edge of crown beams (4) on two sides in a foundation pit (1).

10. The waterproof and drainage construction method of underground cable and PE conduit backfill laying according to any one of claims 1-9, further comprising the following steps after step S5:

step S6: and (2) carrying out backfill construction on the top surface of the foundation pit (1) continuously, enabling the elevation of the top surface of the backfill at the central position of the top surface of the foundation pit (1) to be higher than the elevation of the original ground outside the periphery of the foundation pit (1), forming a backfill soil layer (10) with a herringbone slope surface structure and high in the middle and low in the periphery, and excavating drainage ditches (19) on the original ground outside the periphery of the foundation pit (1).

Background

The power cable laying usually includes various laying modes such as direct-buried laying, cable trench laying, overhead laying, pipe-through laying, underwater laying and the like. In the construction of urban construction engineering, 4 underground YJV22-8.7/15kV-3 x 300mm often need to be laid²The 10kV flexible pipe type high-voltage cables are arranged in a PE (polyethylene) cable protection conduit with DN166mm multiplied by 8.0mm in a penetrating mode and stretch across the top of the underground structure foundation pit. And after the construction of the underground main structure is finished, backfilling and laying construction needs to be carried out on the originally laid 10kV hose type high-voltage cable and the PE guide pipe.

When backfilling and applying facilities are carried out, the prior art adopts more methods: directly backfilling sandy soil or fine soil above and below the high-voltage cable and the PE conduit; or, constructing a sand cushion layer at the bottom of the high-voltage cable and the PE guide pipe, filling stone chips around the sand cushion layer, constructing a concrete cushion layer, a waterproof layer and a reinforced concrete cover plate at the top of the sand cushion layer, and backfilling and tamping soil on the top of the reinforced concrete cover plate to be flush with the ground. However, the methods do not completely solve the problems that surface water on the original ground permeates into backfill soil and a backfill laying ditch and water is easy to accumulate in a ditch of a backfill laying high-voltage cable and a PE (polyethylene) conduit and cannot be discharged out of the backfill laying ditch, and the high-voltage cable and the PE conduit are in a long-term soaking state, so that potential electric leakage and electric shock safety risks are brought to the underground structure during operation.

Disclosure of Invention

The invention provides a waterproof and drainage construction method for backfilling and laying of underground cables and PE (polyethylene) guide pipes, which aims to solve the technical problems that surface water on the original ground easily permeates into a backfilling soil layer and a backfilling laying ditch, water is easily accumulated in the backfilling laying ditch, and the accumulated water cannot be drained in the conventional backfilling laying method.

According to one aspect of the invention, a waterproof and drainage construction method for backfilling laying of underground cables and PE (polyethylene) pipes is provided, which comprises the following steps:

step S1: carrying out field exploration according to the underground structure construction design drawing;

step S2: carrying out underground main structure construction;

step S3: carrying out the paving construction of a backfill soil layer on the underground main body structure, and forming a herringbone slope surface structure with a high middle part and two low sides under the laying trend of the high-voltage cable and the PE guide pipe;

step S4: constructing a waterproof isolation box body on a backfill soil layer of a herringbone slope structure, wherein the waterproof isolation box body is of the herringbone slope structure with a high middle part and two low sides, two sides of the waterproof isolation box body extend out of a foundation pit, and a high-voltage cable and a PE (polyethylene) pipe are installed in the waterproof isolation box body and laid in a herringbone manner;

step S5: and continuing to carry out the paving construction of the backfill soil layer until the top surface of the foundation pit is backfilled.

Further, the step S2 includes the following steps:

step S21: constructing a fender post in the foundation pit except for the design position of the section affected by the positions of the high-voltage cable and the PE guide pipe;

step S22: after the concrete strength of the fender pile reaches the design requirement, constructing a crown beam and a retaining wall;

step S23: carrying out concrete support beam construction;

step S24: carrying out suspension and protection construction on the high-voltage cable and the PE guide pipe;

step S25: after the excavation condition of the foundation pit is checked and accepted, constructing the underground main body;

step S26: after the strength of the top plate concrete of the underground main body reaches the design requirement, the high-voltage cable and the PE guide pipe are dismantled for suspension and protection construction;

step S27: erecting an H-shaped steel pipe supporting platform on the top surface of a top plate of the underground main body to support the bottoms of the high-voltage cable and the PE guide pipe in a jacking mode, and cutting and moving out the concrete supporting beam;

step S28: and constructing a waterproof layer of a top plate coating, a root resistance layer and a fine aggregate concrete waterproof protective layer on the top surface of the underground main body.

Further, the step S3 includes the following steps:

step S31: after the concrete strength of the fine aggregate concrete waterproof protective layer meets the design requirement, paving a backfill soil layer on the fine aggregate concrete waterproof protective layer;

step S32: when a backfill soil layer is paved and constructed to the top surface of the crown beam and the bottoms of the high-voltage cables and the PE guide pipes, breaking the retaining wall in the backfill paving construction section to the top surface of the crown beam, and exposing the high-voltage cables and the PE guide pipes;

step S33: and respectively arranging herringbone slopes outside the two sides of the foundation pit at the central line position of the backfill soil layer under the laying trend of the high-voltage cable and the PE conduit, and calculating and measuring the elevation at the central line position of the foundation pit and the elevations at the top and outer edges of the top beams at the two sides, so that the elevation at the central line position of the foundation pit is higher than the elevations at the top and outer edges of the top beams at the two sides, thereby forming a herringbone slope structure with the middle height and the two sides low.

Further, the following is also included between the step S3 and the step S4:

step S34: and pouring a concrete cushion layer on the backfill soil layer and the top surface of the crown beam, and brushing two waterproof coatings on the surface of the concrete cushion layer to form a waterproof coating.

Further, the step S4 includes the following steps:

step S41: laying a layer of waterproof coiled material on the surface of the waterproof coating in the backfilling laying construction section to form a waterproof isolation layer, and respectively extending the waterproof coiled material to the top outer edges of the crown beams at two sides by 500mm during laying;

step S42: installing a row of positioners at intervals of 500mm from the beam tops of the crown beams on two sides to the position of a central line in the foundation pit on a waterproof isolation layer in a backfill laying construction section, wherein each row of positioners comprises 4 abutted positioners, and the arrangement direction of each row of positioners is vertical to the laying direction of the high-voltage cable and the PE conduit;

step S43: installing the high-voltage cable and the PE guide pipe on the positioner and laying in a herringbone manner, and dismantling the H-shaped steel pipe supporting platform below the high-voltage cable and the PE guide pipe;

step S44: folding the waterproof coiled material along the bottom of the positioner from the outside to the inside by 90 degrees at two sides of the laying direction of the high-voltage cable and the PE conduit in the backfilling laying construction sectionA character shape;

step S45: filling the periphery of the high-voltage cable and the PE conduit to form a drainage filling layer;

step S46: the waterproof coiled material is folded from the outer side to the inner side along the top of the positioner by 90 degrees to form a square shape, and the square shape is wrapped by the high-voltage cable, the PE guide pipe, the positioner and the drainage filling layer to form a waterproof isolation box body with a herringbone slope surface structure, wherein the middle of the box body is high, and the two sides of the box body are low.

Further, the step S45 specifically includes the following steps:

step S451: at the bottom of the high-voltage cable and PE conduitPebbles with the thickness of 50mm are filled in a cavity between the character-shaped waterproof rolls to form a water permeable layer;

step S452: and (3) filling a fine sand layer with the compact thickness of 70mm on the surface of the permeable layer to support the bottoms of the high-voltage cable and the PE conduit, continuously filling the fine sand layer to the top surface of the positioner, and completely covering the high-voltage cable and the PE conduit.

Furthermore, the top surface of locator has seted up U type groove, high tension cable and PE pipe are installed promptly in the U type groove, the bottom surface of locator is seted up at least one and is crossed the water hole.

Further, the distance from the bottom surface of the U-shaped groove to the bottom surface of the positioner is 100 mm-150 mm.

Further, the following is also included between the step S4 and the step S5:

step 45 a: and continuously backfilling soil to the top surface of the waterproof isolation box body at the two outer sides of the waterproof isolation box body in the backfilling construction section, paving sand cushion layers on the top surface of the waterproof isolation box body and the surfaces of the backfilling soil layers, wherein the width of each sand cushion layer exceeds 500mm of each side outside the waterproof isolation box body, constructing reinforced concrete protection plates with herringbone slope surface structures, the middle of each reinforced concrete protection plate is high, the two sides of each reinforced concrete protection plate are low, the width of each reinforced concrete protection plate exceeds 1000mm of each side outside the waterproof isolation box body, and the longitudinal length of each sand cushion layer and each reinforced concrete protection plate exceeds 500mm of each top outer edge of the crown beams at the two sides in the foundation pit.

Further, the following is also included after the step S5:

step S6: and (3) continuing backfilling construction on the top surface of the foundation pit, so that the elevation of the top surface of the backfilling at the central position of the top surface of the foundation pit is higher than the elevation of the original ground outside the periphery of the foundation pit, forming a backfilling soil layer with a herringbone slope structure and high in the middle and low in the periphery, and excavating drainage ditches on the original ground outside the periphery of the foundation pit.

The invention has the following effects:

according to the waterproof and drainage construction method for backfilling and laying the underground cable and the PE guide pipe, the backfill soil layer is laid on the underground main body structure, the herringbone slope surface structure with the high middle part and the low two sides is formed under the laying trend of the high-voltage cable and the PE guide pipe, then the waterproof isolation box body is constructed on the backfill soil layer of the herringbone slope surface structure, the waterproof isolation box body is the herringbone slope surface structure with the high middle part and the low two sides, the ground surface seepage can be prevented from entering the waterproof isolation box body, and the space environment where the high-voltage cable and the PE guide pipe are located is kept dry. And, the both sides of waterproof isolation box extend outside the foundation ditch, and ponding in the waterproof isolation box can be followed the interior bottom surface outflow box of waterproof isolation box outside, and then in discharging the original drainage system outside the foundation ditch, prevent that ponding in the waterproof isolation box from flowing into underground foundation ditch and backfill and lay the ditch in, further ensure the space environment in the waterproof isolation box keeps dry. In addition, the high-voltage cable and the PE guide pipe are laid in the waterproof isolation box body in a herringbone mode, accumulated water in the PE guide pipe can flow into cable wells on two sides outside the foundation pit after flowing out of the inner wall of the guide pipe, and the space environment in the PE guide pipe is kept dry. The waterproof and drainage construction method for backfilling and laying the underground cable and the PE conduit can prevent surface seepage water from permeating into spaces where the high-voltage cable and the PE conduit are located on one hand, and can drain accumulated water in the spaces where the high-voltage cable and the PE conduit are located on the other hand, so that the spaces where the high-voltage cable and the PE conduit are located are kept dry, and the safety accidents of electric leakage and electric shock of the high-voltage cable and the PE conduit due to long-term immersion in water are prevented.

In addition to the objects, features and advantages described above, other objects, features and advantages of the present invention are also provided. The present invention will be described in further detail below with reference to the drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 is a schematic flow chart of a waterproof and drainage construction method for backfilling and laying underground cables and PE pipes according to a preferred embodiment of the present invention.

Fig. 2 is a schematic view of a sub-flow of step S2 in fig. 1.

Fig. 3 is a sub-flowchart of step S3 in fig. 1.

Fig. 4 is a schematic flow chart of a waterproof and drainage construction method for backfilling underground cables and PE pipes according to another embodiment of the present invention.

Fig. 5 is a sub-flowchart of step S4 in fig. 1.

Fig. 6 is a schematic view of the structure of the positioner of the present invention.

Fig. 7 is a sub-flowchart of step S45 in fig. 5.

Fig. 8 is a schematic flow chart of a waterproof and drainage construction method for backfilling underground cables and PE pipes according to another embodiment of the present invention.

Fig. 9 is a schematic flow chart of a waterproof and drainage construction method for backfilling underground cables and PE pipes according to still another embodiment of the present invention.

Fig. 10 is a schematic structural view of a waterproof isolation structure obtained by the waterproof and drainage construction method of underground cable and PE pipe backfill laying according to the present invention.

Fig. 11 is a schematic cross-sectional view taken along line I-I in fig. 10.

Description of the reference numerals

1. A foundation pit; 2. high voltage cables and PE conduits; 3. a fender pile; 4. a crown beam; 5. a retaining wall; 6. a subterranean body; 7. a roof coating waterproof layer; 8. a root resist layer; 9. a fine stone concrete waterproof protective layer; 10. backfilling the soil layer; 11. a concrete cushion; 12. a water-resistant coating; 13. a waterproof isolation layer; 14. a positioner; 15. a drainage filling layer; 16. a water conduit; 17. a sand cushion layer; 18. a reinforced concrete protection plate; 19. a drainage ditch; 141. a U-shaped groove; 142. and a water through hole.

Detailed Description

The embodiments of the invention will be described in detail below with reference to the accompanying drawings, but the invention can be embodied in many different forms, which are defined and covered by the following description.

As shown in fig. 1, a preferred embodiment of the present invention provides a waterproof and drainage construction method for backfilling and laying underground cables and PE pipes, which is characterized by comprising the following steps:

step S1: carrying out field exploration according to the underground structure construction design drawing;

step S2: carrying out underground main structure construction;

step S3: paving a backfill soil layer 10 on the underground main body structure, and forming a herringbone slope surface structure with a high middle part and two low sides under the laying trend of the high-voltage cable and the PE guide pipe 2;

step S4: constructing a waterproof isolation box body on a backfill soil layer 10 of a herringbone slope structure, wherein the waterproof isolation box body is of the herringbone slope structure with a high middle part and two low sides, two sides of the waterproof isolation box body extend out of a foundation pit 1, and a high-voltage cable and a PE (polyethylene) pipe 2 are installed in the waterproof isolation box body and laid in a herringbone manner;

step S5: and continuing the paving construction of the backfill soil layer 10 until the top surface of the foundation pit 1 is backfilled.

It can be understood that the waterproof and drainage construction method for backfilling and laying of the underground cable and the PE conduit according to the embodiment includes the steps of performing paving construction of a backfill soil layer 10 on an underground main structure, forming a herringbone slope structure with a high middle part and two low sides under the laying trend of the high-voltage cable and the PE conduit 2, and performing construction of a waterproof isolation box body on the backfill soil layer 10 of the herringbone slope structure, wherein the waterproof isolation box body is the herringbone slope structure with the high middle part and the two low sides, so that surface seepage can be prevented from entering the waterproof isolation box body, and the space environment where the high-voltage cable and the PE conduit 2 are located is kept dry. And, the both sides of waterproof isolation box extend outside foundation ditch 1, and ponding in the waterproof isolation box can be followed the interior bottom surface outflow box of waterproof isolation box outside, and then arrange into the outer original drainage system of foundation ditch 1 in, prevent that ponding in the waterproof isolation box from flowing into underground foundation ditch 1 and backfilling lays in the ditch, further ensures the space environment in the waterproof isolation box keeps dry. In addition, the high-voltage cable and the PE guide pipe 2 are laid in the waterproof isolation box body in a herringbone mode, accumulated water in the PE guide pipe can flow out along the inner wall of the guide pipe and then flow into cable wells on two sides outside the foundation pit 1, and the space environment in the PE guide pipe is kept dry. The waterproof and drainage construction method for backfilling and laying the underground cable and the PE guide pipe can prevent surface seepage water from permeating into the space where the high-voltage cable and the PE guide pipe 2 are located on one hand, and can drain accumulated water in the space where the high-voltage cable and the PE guide pipe 2 are located on the other hand, so that the space where the high-voltage cable and the PE guide pipe 2 are located is kept dry, and the safety accidents of electric leakage and electric shock of the high-voltage cable and the PE guide pipe 2 caused by long-term immersion in water are prevented. The slope of the two slope surfaces of the herringbone structure is preferably 1.5%, and of course, in other embodiments of the present invention, the slope may be set to other values, such as 2%, 1%, and the like. It is understood that all chevron configurations have equal slope slopes unless specifically described in the present disclosure.

It can be understood that, in step S1, taking the construction of the underground structure of a certain track traffic station in Guangxi as an example, according to the design of the underground structure construction drawing of the station, the underground laying depth, position, diameter, material, laying direction, cable well position, high-voltage switching station position and surrounding environment conditions of the 10kV hose-type high-voltage cable and the PE pipe 2 are investigated and detected in detail, especially the laying direction, cable well position and high-voltage switching station position of the high-voltage cable and the PE pipe 2 are mainly investigated, a property unit is informed and invited to send a person to perform field guidance, construction is performed strictly according to the requirements of the property unit, a special person is required to be arranged to be in butt joint with the property unit, and the condition is reported to the property unit to be processed in time.

It is understood that, as shown in fig. 2, the step S2 includes the following steps:

step S21: constructing a fender post 3 in the foundation pit 1 except for the design position of the section affected by the positions of the high-voltage cable and the PE guide pipe 2;

step S22: after the concrete strength of the fender post 3 reaches the design requirement, constructing the crown beam 4 and the retaining wall 5;

step S23: carrying out concrete support beam construction;

step S24: carrying out suspension and protection construction on the high-voltage cable and the PE guide pipe 2;

step S25: after the excavation condition of the foundation pit 1 is checked and accepted, constructing the underground main body 6;

step S26: after the strength of the top plate concrete of the underground main body 6 reaches the design requirement, the high-voltage cable and the PE guide pipe 2 are removed for suspension and protection construction;

step S27: erecting an H-shaped steel pipe supporting platform on the top surface of a top plate of the underground main body 6 to support the bottoms of the high-voltage cable and the PE guide pipe 2 in a jacking mode, and cutting and moving out the concrete supporting beam;

step S28: the top surface of the underground body 6 is provided with a top plate coating waterproof layer 7, a root resistance layer 8 and a fine aggregate concrete waterproof protective layer 9.

In the step S21, according to the design of the underground structure construction drawing, in the foundation pit 1 of the underground structure, the fender pile 3 of C30 underwater concrete is constructed at the design position of the fender pile 3 of the section except for the position affected by the high-voltage cable and the PE conduit 2.

In the step S22, for the section affected by the high-voltage cable and the position of the PE conduit 2, after the strength of the concrete of the fender pile 3 meets the design requirement, the pile head concrete of the fender pile 3 is broken, and the integrity of the pile body of the fender pile 3 is detected. After the pile body of the fender post 3 is detected to be qualified, a C20 concrete cushion, a C30 concrete crown beam 4 and a retaining wall 5 are constructed on the top surface of the fender post 3.

And for the section influenced by the positions of the high-voltage cable and the PE guide pipe 2, the design positions of the section influenced by the positions of the high-voltage cable and the PE guide pipe 2 in the foundation pit 1 and without constructing the top beam 4 and the retaining wall 5 are respectively vertical to the laying trend of the high-voltage cable and the PE guide pipe 2, an excavation method with mechanical excavation as a main part and manual cooperation as an auxiliary part is adopted, and a groove with the width of an upper opening of 7000mm, the width of a lower opening of 2000mm, the depth of 250mm below the bottom of the top beam 4 and the slope gradient of 1:1 is excavated. Then, a C20 concrete pad was applied to the top surface of the trench, and a C30 concrete cap beam 4 was applied to the top surface of the concrete pad. Then, the high voltage cable and the PE pipe 2 crossing the retaining wall 5 are installed on the structural reinforcement frame of the retaining wall 5 at a position 150mm from the top surface of the crown beam 4, the structural reinforcement and the formwork of the retaining wall 5 are installed at positions 50mm from the peripheries of the high voltage cable and the PE pipe 2, respectively, and C30 concrete is poured to form the retaining wall 5, so that the concrete of the retaining wall 5 entirely wraps the peripheries of the high voltage cable and the PE pipe 2, and the high voltage cable and the PE pipe 2 are supported and supported after the concrete of the retaining wall 5 is molded.

In step S23, C30 concrete is applied to the designed position of the concrete support beam in the foundation pit 1 to form the support beam.

In step S24, the construction technician must perform the suspension installation and protection of the high voltage cable and the PE pipe 2 on the construction site strictly according to the approved suspension and protection scheme of the high voltage cable and the PE pipe 2.

In step S25, after the excavation condition of the foundation pit 1 is accepted, the earth and rockwork excavation, the pile-slab wall, the inter-pile spray anchor, the foundation acceptance, the bottom-slab cushion layer, the bottom-slab waterproof layer, and the construction of the underground main body 6 (including the bottom slab, the wall, and the top slab) in the foundation pit 1 of the underground structure can be performed.

In step S26, after the strength of the roof concrete of the underground main body 6 reaches the design requirement, the protection and suspension of the high-voltage cable and the PE pipe 2 are removed.

In the step S27, after the H-shaped steel pipe supporting platform is erected on the top surface of the top plate of the underground main body 6 to support the bottom of the high-voltage cable and the PE pipe 2, the concrete supporting beam is cut and removed by a sectional cutting and parallel moving method. When the concrete support beam is cut and removed, the high-voltage cable and the PE guide pipe 2 are strictly prohibited from being collided and torn, and electric shock accidents occur.

In the step S28, a roof paint waterproof layer 7, a root resistance layer 8 and a C20 fine aggregate concrete waterproof layer 9 with a thickness of 100mm in a section other than the section affected by the position of the H-shaped steel pipe supporting platform are applied to the top surface of the roof of the underground main body 6, after the concrete strength of the fine aggregate concrete waterproof layer 9 meets the design requirements, the H-shaped steel pipe supporting platform is erected again on the surface of the fine aggregate concrete waterproof layer 9 to support the high-voltage cable and the bottom of the PE pipe 2, the originally erected H-shaped steel pipe supporting platform is dismantled, and the roof paint waterproof layer 7, the root resistance layer 8 and the C20 fine aggregate concrete waterproof layer 9 with a thickness of 100mm in the remaining section are applied. And wetting and maintaining the concrete of the fine aggregate concrete waterproof protective layer 9 for 7 days by adopting geotextile after the concrete is finally set.

It is understood that, as shown in fig. 3, the step S3 includes the following steps:

step S31: after the concrete strength of the fine aggregate concrete waterproof protective layer 9 meets the design requirement, paving a backfill soil layer 10 on the fine aggregate concrete waterproof protective layer 9;

step S32: when the backfill soil layer 10 is paved and constructed to the top surface of the crown beam 4 and the bottom of the high-voltage cable and the PE guide pipe 2, breaking the retaining wall 5 in the backfill paving construction section to the top surface of the crown beam 4, and exposing the high-voltage cable and the PE guide pipe 2;

step S33: and respectively arranging herringbone slopes outside the two sides of the foundation pit 1 at the central line position of the backfill soil layer 10 running right below the laying direction of the high-voltage cable and the PE conduit 2, and calculating and measuring the elevation at the central line position of the foundation pit 1 and the elevations at the top outer edges of the top beams 4 at the two sides, so that the elevation at the central line position of the foundation pit 1 is higher than the elevations at the top outer edges of the top beams 4 at the two sides, thereby forming a herringbone slope structure with a high middle part and low two sides.

In step S31, after the concrete strength of the fine aggregate concrete waterproof layer 9 to be later constructed on the top plate of the underground main body 6 meets the design requirement, backfill paving construction is performed on the fine aggregate concrete waterproof layer 9. When in paving construction, mechanical layered paving and mechanical rolling are adopted, and manual layered paving and tamping are adopted under the high-voltage cable and the PE guide pipe 2. Wherein, the paving thickness of each layer is as follows: the thickness is 300mm when mechanical rolling is adopted, the thickness is 150mm when a tamper is adopted, and the compactness of each layer reaches more than 90%.

In step S32, when the backfill soil layer 10 in the foundation pit 1 is constructed to the top surface of the crown beam 4 and the bottom of the high-voltage cable and the PE pipe 2, the retaining wall 5 in the backfill construction section is broken to the top surface of the crown beam 4, and the high-voltage cable and the PE pipe 2 are exposed. When the retaining wall 5 is broken, the high-voltage cable and the PE conduit 2 are strictly prevented from being broken.

In the step S33, at the central line position of the backfill soil layer 10 directly below the laying direction of the high-voltage cable and the PE pipe 2 in the backfill laying construction section, a reversed-V-shaped slope with a slope of 1.5% is respectively arranged outside both sides of the foundation pit 1. And calculating and measuring the elevation at the position of the central line in the foundation pit 1 and the elevations at the top outer edges of the top beams 4 at two sides in the foundation pit 1, so that the elevation at the position of the central line in the foundation pit 1 is higher than the elevations at the top outer edges of the top beams 4 at two sides. When the backfill soil layer 10 in the underground structure foundation pit 1 is constructed, manual accurate leveling and tamping are adopted, so that the elevation of the position of the central line in the foundation pit 1 is higher than the elevations of the top outer edges of the top beams 4 at the two sides, and the backfill soil layer 10 with the reversed V-shaped slope structure, which is 'high in the middle and low in the top outer edges of the top beams 4 at the two sides', is formed in the foundation pit 1.

It is understood that, as shown in fig. 4, in another embodiment of the present invention, the method for constructing water-proof and drainage by backfilling underground cables and PE conduits further includes the following steps between the step S3 and the step S4:

step S34: and pouring a concrete cushion 11 on the top surfaces of the backfill soil layer 10 and the crown beam 4, and brushing two waterproof coatings on the surface of the concrete cushion 11 to form a waterproof coating 12.

Specifically, concrete slag on the top surfaces of the crown beams 4 on two sides in the underground structure foundation pit 1 is cleaned in the backfill laying construction section, and a C20 concrete cushion layer 11 with the thickness of 100mm is poured on the backfill soil layer 10 and the top surfaces of the crown beams 4. And then, painting a second SY-J CCCW C type cement-based permeable crystallization type waterproof coating on the surface of the concrete cushion layer 11 to form a waterproof coating 12. When the waterproof coating 12 is coated, the base surface of the concrete cushion 11 is wetted to form internal saturation, the base surface cannot have redundant floating water, the subsequent coating is carried out after the previous coating is cured for 24 hours, and the subsequent coating direction is perpendicular to the previous coating direction. And when the cement-based permeable crystalline waterproof coating is cured to be not damaged by sprayed water, using the wet geotextile for curing for 3 days.

Preferably, the step S34 further includes the following steps: and water guide pipes 16 are arranged on two sides outside the foundation pit 1, particularly on the outer sides of the tops of the crown beams 4 on two sides, so that water flowing out of the concrete cushion 11 and the waterproof coating 12 is guided into an original drainage system of the foundation pit 1.

It is understood that, as shown in fig. 5, the step S4 includes the following steps:

step S41: laying a layer of waterproof coiled material on the surface of the waterproof coating 12 in the backfilling laying construction section to form a waterproof isolation layer 13, and respectively extending the waterproof coiled material 500mm towards the top outer edges of the crown beams 4 at two sides during laying;

step S42: on a waterproof isolation layer 13 in a backfill laying construction section, a row of locators 14 is arranged at intervals of 500mm from beam tops of crown beams 4 on two sides to the position of a central line in a foundation pit 1, each row of locators 14 comprises 4 abutted locators 14, and the arrangement direction of each row of locators 14 is vertical to the laying direction of a high-voltage cable and a PE (polyethylene) pipe 2;

step S43: installing the high-voltage cable and the PE guide pipe 2 on the positioner 14 and laying in a herringbone manner, and removing the H-shaped steel pipe supporting platform below the high-voltage cable and the PE guide pipe 2;

step S44: in the backfill laying construction section, along the laying direction of the high-voltage cable and the PE conduit 2, the two sides turn over the waterproof coiled material from the outer side to the inner side by 90 degrees along the bottom of the positioner 14A character shape;

step S45: filling the periphery of the high-voltage cable and the PE guide pipe 2 to form a drainage filling layer 15;

step S46: the waterproof coiled material is turned over by 90 degrees from the outer side to the inner side along the top of the positioner 14 to form a square shape, and the waterproof coiled material is wrapped on the high-voltage cable, the PE conduit 2, the positioner 14 and the drainage filling layer 15 to form a waterproof isolation box body with a herringbone slope surface structure, wherein the middle of the waterproof isolation box body is high, and the two sides of the waterproof isolation box body are low.

In the step S41, a layer of H-shaped polyvinyl chloride (PVC) waterproof roll with a specification of 1.5mm × 4000mm × 25500mm is laid on the surface of the waterproof coating 12 in the backfill laying construction section to form the waterproof isolation layer 13. The lapping length between the waterproof rolls is 200mm, and the lapping seam is pasted and sealed by double-sided sticky butyl rubber self-adhesive waterproof rolls with the specification of 1.5mm multiplied by 500mm multiplied by 20000 mm. When laying, the waterproofing membrane extends 500mm to the top outward flange of the both sides crown beam 4 in the underground structure foundation ditch 1 respectively, is favorable to the earth's surface infiltration in the waterproof isolation box to freely flow out of the waterproof isolation box through the waterproof isolation bottom of the box, directly flows into in the original drainage system outside the foundation ditch 1, makes the interior space environment of waterproof isolation box keep dry, prevents that the earth's surface infiltration in the waterproof isolation box from flowing into backfill soil layer 10 and backfill laying in the foundation ditch 1.

In the step S42, a row of locators 14 is installed every 500mm from the beam tops of the crown beams 4 on both sides to the position of the center line in the foundation pit 1 on the waterproof isolation layer 13 in the backfill laying construction section, each row of locators 14 includes 4 next-to-next locators 14, the arrangement direction of each row of locators 14 is perpendicular to the laying direction of the high-voltage cables and the PE pipes 2, the multiple rows of locators 14 construct a framework structure of the waterproof isolation box body, support the waterproof coiled material to form a box body structure, and then improve the overall rigidity of the waterproof isolation box body together with the subsequent drainage filling layer 15. As shown in fig. 6, a U-shaped groove 141 is formed in the top surface of the locator 14, the high-voltage cable and the PE conduit 2 are installed in the U-shaped groove 141, and at least one water passing hole 142 is formed in the bottom surface of the locator 14, so that accumulated water in the waterproof isolation box can flow freely. Preferably, the number of the water through holes 142 is two. In addition, the distance from the bottom surface of the U-shaped groove 141 to the bottom surface of the positioner 14 is 100 mm-150 mm, preferably 120mm, so that accumulated water in the waterproof isolation box can freely flow out of the waterproof isolation box through the pebble permeable layer, the fine sand layer and the surface of the waterproof roll material at the bottom, and the space environment in the waterproof isolation box is kept dry. The locator 14 is a C30 reinforced concrete precast block, the length, the width and the height of the locator are 350mm, 200mm and 350mm, the depth of the U-shaped groove 141 is 230mm, the width of the U-shaped groove is 180mm, the water passing holes 142 are semicircular holes with the radius of 50mm, and the interval between the two water passing holes 142 is 50 mm. In addition, the bottom surface of the U-shaped groove 141 is a slope surface, and the slope of the slope surface is consistent with the slope of the top surface of the locator 14, so that water accumulation in the U-shaped groove 141 is prevented. Namely, the slope of the top surface of the locator 14 is 1.5%, the bottom surface of the locator 14 is parallel to the top surface of the locator 14, which is beneficial to the installation stability of the locator 14, the high-voltage cable and the PE conduit 2 on the surface of the herringbone waterproof isolation layer 13, and is also beneficial to the top surface and the bottom surface of the constructed waterproof isolation box body to be 1.5% slope surfaces which are parallel to each other.

In step S43, when the positioner 14 is installed, the U-shaped groove 141 is upward, the two water holes 142 are downward, the H-shaped steel tube supporting platform directly below the high-voltage cable and the PE pipe 2 is removed, and 4 high-voltage cables and PE pipes 2 are respectively placed in the U-shaped groove 141 of the positioner 14, so that a cavity of 120mm is formed between the bottom of each of the high-voltage cable and PE pipe 2 and the surface of the waterproof isolation layer 13. After installation, the high-voltage cable and the PE guide pipe 2 are in a shape that 4 are closely laid side by side on the plane of the foundation pit 1.

It can be understood that, as shown in fig. 7, the step S45 specifically includes the following steps:

step S451: at the bottom of the high-voltage cable and the PE conduit 2 andpebbles with the thickness of 50mm are filled in a cavity between the character-shaped waterproof rolls to form a water permeable layer;

step S452: and (3) filling a dense fine sand layer with the thickness of 70mm on the surface of the permeable layer to support the bottom of the high-voltage cable and the PE conduit 2, continuously filling the fine sand layer to the top surface of the positioner 14, and completely covering the high-voltage cable and the PE conduit 2.

Specifically, inIn a cavity between the bottom of the high-voltage cable and the PE conduit 2 on the inner side of the character-shaped waterproof coiled material and the waterproof coiled material, pebbles with the nominal single particle grade of 16-25 mm and the thickness of 50mm, large gaps and strong water permeability are filled to form a water permeable layer, a fine sand layer with the dense thickness of 70mm is filled on the surface of the water permeable layer to support the bottom of the high-voltage cable and the PE conduit 2, fine sand is filled on the top surface of the fine sand layer to the top surface of the positioner 14, and the high-voltage cable and the PE conduit 2 are completely covered.

It can be understood that in the direction ofThe inner side of the character-shaped waterproof coiled material is filled with pebbles and fine sand, and simultaneouslyAnd a backfill soil layer 10 is paved on the outer side of the character-shaped waterproof roll to support the turnover of the waterproof roll. The lapping length between the waterproof rolls is 200mm, and the lapping seam is pasted and sealed by double-sided sticky butyl rubber self-adhesive waterproof rolls with the specification of 1.5mm multiplied by 500mm multiplied by 20000 mm.

It can be understood that, a construction technician sets the high-voltage cable and the PE conduit 2 to be a backfill laying construction section within a range extending by 1000mm from two sides of the laying width of the high-voltage cable and the PE conduit 2 under the laying direction of the high-voltage cable and the PE conduit 2 in the underground structure foundation pit 1. The length of the backfilling laying construction section is the distance between the crown beams 4 at two sides along the laying direction of the high-voltage cable and the PE conduit 2, and the width is 3400mm, namely: the laying width of the 4 high-voltage cables and the PE guide pipe 2 is 4 multiplied by 350mm, the high-voltage cables and the PE guide pipe 2 extend 1000mm outside two sides respectively, and the length of each locator 14 is 350 mm.

It is understood that, as shown in fig. 8, in another embodiment of the present invention, the method for constructing water-proof and drainage by backfilling underground cables and PE pipes further includes the following steps between the step S4 and the step S5:

step 45 a: and continuously backfilling soil to the top surface of the waterproof isolation box body at the two outer sides of the waterproof isolation box body in the backfilling construction section, paving a sand cushion layer 17 on the top surface of the waterproof isolation box body and the surface of the backfilling soil layer 10, wherein the width of the sand cushion layer 17 exceeds 500mm of each side outside the waterproof isolation box body, constructing a reinforced concrete protection plate 18 with a herringbone slope surface structure with a high middle part and two low sides on the surface of the sand cushion layer 17, the width of the reinforced concrete protection plate 18 exceeds 1000mm of each side outside the waterproof isolation box body, and the longitudinal length of the sand cushion layer 17 and the longitudinal length of the reinforced concrete protection plate 18 exceed 500mm of each side of the top outer edge of the crown beams 4 at two sides in the foundation pit 1.

Specifically, a backfilling soil layer 10 is manually paved in 2 layers and tamped to the top surface of the waterproof isolation box body by a tamping machine at two outer sides of the waterproof isolation box body in the foundation pit 1 in the backfilling laying construction section. And paving a sand cushion layer 17 with the thickness of 100mm on the top surface of the waterproof isolation box body and the surface of the backfill soil layer 10, wherein the width of the sand cushion layer 17 exceeds each side of the waterproof isolation box body by 500 mm. A C30 reinforced concrete protection plate 18 with the thickness of 150mm and the 1.5% slope inclined downward Y-shaped slope with the middle high and the two side crown beams 4 low is arranged on the surface of the sand cushion layer 17, the width of the reinforced concrete protection plate 18 exceeds each side of the waterproof isolation box body by 1000mm, and the longitudinal length of the sand cushion layer 17 and the reinforced concrete protection plate 18 exceeds each side of the top outer edges of the two side crown beams 4 in the foundation pit 1 by 500 mm. The reinforced concrete protection plate 18 with the reversed V-shaped slope surface structure has the function of draining accumulated water in the backfill soil layer 10 besides the waterproof isolation box body, is favorable for refilling the accumulated water in the backfill soil layer 10 in the construction section, freely flows into the original drainage system outside the foundation pit 1 along the top surface of the reversed V-shaped slope reinforced concrete protection plate 18 with the gradient of 1.5 percent, and prevents the accumulated water in the backfill soil layer 10 from permeating into the waterproof isolation box body.

It is to be understood that in the step S5, in the backfill soil layer 10 laying, the backfill soil is laid to the top surface of the foundation pit 1 by using mechanical layered paving and mechanical rolling. The paving thickness of each layer is 300mm, and the compactness of each layer reaches more than 90%.

It is understood that, as shown in fig. 9, in another embodiment of the present invention, the method for constructing water-proof and drainage by backfilling underground cables and PE pipes further includes the following steps after step S5:

step S6: and (3) continuing backfilling construction on the top surface of the foundation pit 1, enabling the elevation of the top surface of the backfilling at the central position of the top surface of the foundation pit 1 to be higher than the elevation of the original ground outside the periphery of the foundation pit 1, forming a backfilling layer 10 with a herringbone slope structure and high in the middle and low in the periphery, and excavating a drainage ditch 19 on the original ground outside the periphery of the foundation pit 1.

Specifically, when the backfill soil layer 10 is paved on the top surface of the foundation pit 1, the backfill soil is paved mechanically, the elevation of the top surface of the backfill soil is leveled manually and accurately, and the backfill soil is compacted by rolling mechanically, so that the elevation of the top surface of the backfill soil layer 10 is higher than the elevation of the original ground outside the periphery of the top surface of the foundation pit 1, the backfill soil layer 10 with a slope of a herringbone shape with a gradient of 1.5% and a height of high in the middle and low outside the periphery is formed, and drainage ditches 19 are excavated on the original ground outside the periphery of the foundation pit 1. The surface water on the top surface of the foundation pit 1 is drained into the drainage ditch 19 outside the foundation pit 1 in time through the backfill soil layer 10 with the herringbone slope surface structure and is led into the original drainage system, and the surface water on the top surface of the foundation pit 1 is prevented from permeating into the backfill soil layer 10 and the backfill laying ditch.

It can be understood that, as shown in fig. 10 and 11, the waterproof isolation structure obtained by the waterproof and drainage construction method of underground cable and PE pipe backfill laying of the present invention has four layers of waterproof and drainage structures, namely, a backfill soil layer 10 with a herringbone slope structure, a concrete cushion layer 11 and a waterproof coating layer 12 under the waterproof isolation box body, a waterproof isolation box body with a herringbone slope structure, a reinforced concrete protection plate 18 with a herringbone slope structure, and a backfill soil layer 10 with a herringbone slope structure over the waterproof isolation box body. The design of the waterproof isolation box body with the herringbone slope surface is favorable for the surface seepage water in the waterproof isolation box body to freely flow out of the waterproof isolation box body through the fine sand layer, the pebble permeable layer and the surface of the waterproof coiled material at the bottom of the box body and directly flow into the original drainage system outside the foundation pit 1, so that the space environment in the waterproof isolation box body is kept dry, and the surface seepage water in the waterproof isolation box body is prevented from flowing into the backfill soil layer 10 and the backfill laying ditch below; meanwhile, accumulated water in the PE (polyethylene) cable protection guide pipe at the periphery of the high-voltage cable can be accumulated, and the inclined inverted V-shaped slope with the gradient of 1.5 percent and the lower gradient at the high middle part and the low two sides can freely flow into the cable wells at the two sides outside the foundation pit 1 after backfilling and laying, so that the space environment in the PE (polyethylene) cable protection guide pipe can be kept dry; (2) the design of the backfill soil layer 10, the concrete cushion layer 11 and the waterproof coating 12 on the reversed V-shaped slope is beneficial to the water seepage on the ground surface outside the waterproof isolation box body or in the backfill soil layer 10, the water seepage freely flows out of the top outer edges of the crown beams 4 on two sides through the concrete cushion layer 11 and the waterproof coating 12 on the reversed V-shaped slope, and the water seepage on the ground surface is introduced into the original drainage system through the water conduit 16; (3) the design of the reinforced concrete protection plate 18 on the reversed V-shaped slope is beneficial to accumulating water in the backfill soil layer 10 on the upper layer, and the top surface of the reinforced concrete protection plate 18 on the reversed V-shaped slope along the slope of 1.5 percent freely flows into the original drainage system outside the foundation pit 1, so that the accumulated water in the backfill soil layer 10 above the top is prevented from permeating into the waterproof isolation box body; (4) the design of the top layer of the backfill soil layer 10 of the reversed V-shaped slope is beneficial to timely discharging surface water into the drainage ditch 19 outside the foundation pit 1 through the top layer of the backfill soil layer 10 of the reversed V-shaped slope with the gradient of 1.5 percent and leading the surface water into the original drainage system, so that the surface water on the top surface of the foundation pit 1 is prevented from permeating into the backfill soil layer 10 and the backfill laying ditch.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.