Composite protection structure for treatment and repair of slope disease area and construction method

Abstract

The invention discloses a composite protection structure, particularly relates to a composite protection structure for treating and repairing a slope disease area and a construction method, and belongs to the technical field of design and construction of slope treatment engineering structures. According to the composite protection structure for treatment and repair of the slope disease area and the construction method, construction is convenient and fast, the anti-sliding capacity is high, and the construction cost is low. The composite protection structure comprises strongly-moderately-weathered mudstone and a water-rich loose collapse slope product obliquely pressed on a strongly-moderately-weathered mudstone side slope, the composite protection structure further comprises an enhanced protection system and a draining back pressure stability augmentation system, and the enhanced protection system is inserted into the portion, at the root of the strongly-moderately-weathered mudstone, of the side slope through the lower portion of the enhanced protection system. The draining back pressure stability augmentation system obliquely pressed on the strongly and moderately weathered mudstone side slope blocks and drains underground seepage water in the side slope by enhancing a protection system.

Description

Technical Field

[0001] The present invention relates to a composite protective structure, in particular to a composite protective structure for treating and repairing a slope diseased area, belonging to the technical field of design and construction of slope treatment engineering structures. The present invention also relates to a construction method for the composite protective structure for treating and repairing a slope diseased area. Background Art

[0002] Retaining walls are very common retaining structures in the process of roadbed construction, and they play an important role in the protection of road cuttings and embankments in roadbed projects. After the development in recent years, steel pipe columns have been increasingly used in roadbed retaining structures due to their unique economic advantages and operational protection advantages, but they are mostly used in narrow working surfaces or roadbed disease treatment. Due to their small disturbance to the slope during construction and fast construction speed, they are increasingly used in the treatment of slopes with larger diseases.

[0003] The patent with publication number CN202010552625.4 discloses a combined protective structure of a slope retaining wall and steel pipe piles and a construction method thereof, comprising steel pipe piles, a retaining pedestal and a retaining wall arranged in sequence from bottom to top along the direction of the slope to be supported, wherein one end of the steel pipe pile is pre-buried in the bearing layer of the underground soil; the other end is connected to the upper part of the retaining pedestal, and a plurality of retaining walls are cast on the top of the retaining pedestal, and the plurality of retaining walls are spliced ​​together and are adjacent to the slope surface of the slope to be supported; wherein fillers are cast or filled in the steel pipe piles; and a plurality of reinforcing support members are arranged in a ring on the outer wall of the upper end of the steel pipe piles. This application can penetrate complex strata, is not affected by underground obstacles, can achieve any slope, and can be suitable for various soil conditions. The C30 buttress wall has good integrity and high strength. The grouting micro-piles are easy to construct. The grouting micro-piles act as anti-slip convex tenons and at the same time, the grouting micro-piles also play a role in reinforcing and locking the rock strata, increasing the friction resistance between the buttress wall and the rock mass, saving economic costs while ensuring safety.

[0004] The patent with publication number CN201921936878.0 discloses a micro steel pipe pile retaining wall anti-sliding support structure, including a buttress retaining wall for slope management and built with reinforced concrete, at the bottom of the buttress retaining wall, there are no less than four rows of micro steel pipe piles arranged in a rectangular shape, an anchor rod is arranged on the inner side of the buttress retaining wall, and a concrete baffle is arranged at the bottom of the anchor rod. The top of the micro steel pipe pile is connected to the bottom of the buttress retaining wall with steel bars, and the bottom of the micro steel pipe pile extends into the stable rock formation; the micro steel pipe pile is provided with micro pile holes arranged in a spiral shape along the length direction of the steel pipe. This application solves the problem that the earthwork engineering volume in the existing retaining wall anti-sliding technology cannot be controlled and cannot be applied to projects with limited site space. The utility model can appropriately reduce the bottom surface size and foundation burial depth of the retaining wall foundation, and also reduce the amount of earthwork excavation, effectively saving construction period and engineering cost, and has strong applicability in high slope graded support projects.

[0005] The above patents all use a combination of buttress retaining walls and steel pipe piles, which require a larger working surface, and the main load-bearing support structure is the buttress retaining wall. The steel pipe piles play an auxiliary role in preventing slipping and ensuring foundation requirements to a greater extent. The retaining wall and the steel pipe piles use a pedestal to transmit force, so the structure is relatively complex, the construction process is relatively complex, and there are great limitations. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a composite protective structure and construction method for treating and repairing slope diseased areas, which has convenient and fast construction, strong anti-slip ability and low engineering cost, as well as a construction method for the composite protective structure for treating and repairing slope diseased areas.

[0007] The technical solution adopted to solve the above technical problems is: a composite protective structure for treating and repairing slope disease areas, including strongly moderately weathered mudstone and water-rich loose landslide accumulation obliquely pressed on the strongly moderately weathered mudstone slope. The composite protective structure also includes an enhanced protection system and a drainage counter-pressure stabilization system. The enhanced protection system is inserted into the slope at the root of the strongly moderately weathered mudstone through its lower part, and the drainage counter-pressure stabilization system obliquely pressed on the strongly moderately weathered mudstone slope blocks and drains underground seepage water through the enhanced protection system.

[0008] Furthermore, the access roadbed is arranged outside the enhanced protection system, and the access roadbed is inclined at least 2% toward the enhanced protection system along the width direction, and a drainage ditch is provided at least at the junction of the access roadbed and the enhanced protection system.

[0009] The preferred embodiment of the above scheme is that the drainage back pressure stabilization system is a back pressure crushed stone filled on the side surface of the water-rich loose landslide slope in cooperation with the enhanced protection system, and the angle between the back pressure crushed stone pressing surface and the horizontal plane is between 40° and 50°.

[0010] Furthermore, the enhanced protection system includes a lower plug-in support and stabilization component and an upper retaining and draining component. The upper part of the plug-in support and stabilization component is embedded in the lower retaining and draining component. The enhanced protection system is plugged into the slope at the root of the strongly to moderately weathered mudstone through the plug-in support and stabilization component. At least the drainage back pressure stabilization system is supported, drained and maintained stable by the retaining and draining component.

[0011] The preferred embodiment of the above scheme is that the retaining and drainage assembly is composed of a light buttress type cast-in-place retaining wall, and a plurality of downward inclined drainage holes are arranged on the light buttress type cast-in-place retaining wall. The flocculent seepage water and underground seepage water in the water-rich loose landslide accumulation and the strongly medium weathered mudstone are discharged to the outside of the light buttress type cast-in-place retaining wall through the drainage back pressure stabilization system.

[0012] Furthermore, the plug-in support stabilization component includes a plurality of support stabilization piles sequentially embedded in the root slope of the strongly to moderately weathered mudstone along the length direction, and the upper part of each support stabilization pile is respectively embedded in the wall body of the lower part of the light buttress-type cast-in-place retaining wall at the corresponding position.

[0013] The preferred embodiment of the above scheme is that there are two rows of supporting stabilization piles embedded in the root slope of strongly to moderately weathered mudstone along the length direction, the distance between two adjacent supporting stabilization piles in each row is not less than 1m, the row spacing between the two rows of supporting stabilization piles is not less than 0.5m and they are staggered, the length of each supporting stabilization pile inserted into the slope is not less than 5m, and the length extending out of the slope is between 2.5 and 3.5m.

[0014] Furthermore, each supporting stabilizing pile is composed of a composite steel pipe pile, and each composite steel pipe pile is sequentially embedded in the slope at the root of the strong and medium weathered mudstone along the length direction of the slope.

[0015] Each composite steel pipe pile includes three steel pipes and three groups of reinforced concrete filling bodies. Grouting holes are respectively arranged at the lower end of each steel pipe. Each steel pipe is spot-welded into a whole through multiple groups of connecting steel bars arranged at intervals along its length direction. Each steel pipe is filled with a corresponding group of reinforced concrete filling bodies. Each composite steel pipe pile combined into a whole is filled with fixed grouting bodies between the strongly and moderately weathered mudstone at the corresponding position and the outer wall of the composite steel pipe pile through the grouting holes.

[0016] The construction method of the composite protective structure used for the treatment and repair of the slope disease area is characterized in that: the construction method comprises the following steps:

[0017] 1) Select down-the-hole drilling rigs and grouting machines according to design requirements, conduct appearance inspection and quality assurance acceptance of steel pipe piles, and level the construction site;

[0018] 2) Drilling, installing steel pipes and grouting to form steel pipe piles,

[0019] 3) After the slurry meets the specified strength requirements, a light retaining wall formwork is set up to pour the retaining wall concrete. During the pouring process, drainage holes are left layer by layer as required;

[0020] 4) After the strength of the retaining wall meets the requirements, gravel backfill is carried out on the back of the wall to complete the construction of the composite protective structure.

[0021] Furthermore, drilling and grouting to form the steel pipe column is carried out according to the following steps:

[0022] a. Put the drilling rig in place, measure the center point of the pile position according to the design drawing, and align the drilling rig steadily after ensuring that the hole position is correct;

[0023] b. Drilling: Use a drilling rig to drill. During the drilling process, check the ground conditions at any time to select the drilling frequency. After reaching the designed elevation, confirm with the relevant parties;

[0024] c. Steel pipe hoisting: After professional technicians weld and form the steel pipe piles in plum blossom shape, transport them to the site, hold the steel pipe and the internal steel bars firmly, and then slowly lower them to the hole. If there is any obstruction, find out the cause and correct it;

[0025] d. Slurry preparation and grouting. Prepare the slurry according to the mix ratio and use the grouting pipe to inject the slurry into the bottom of the hole. After the grouting is completed, use high-pressure water to flush the grouting pipe to prevent blockage to complete the construction work of drilling and grouting to form steel pipe piles.

[0026] The beneficial effects of the present invention are as follows: the technical solution provided by the present application is based on the existing strongly moderately weathered mudstone and the water-rich loose landslide accumulation obliquely pressed on the slope of the strongly moderately weathered mudstone, and a composite protection structure of the present application is formed by adding an enhanced protection system and a drainage back pressure stabilization system, and then the enhanced protection system is inserted into the slope at the root of the strongly moderately weathered mudstone through its lower part, and the drainage back pressure stabilization system obliquely pressed on the slope of the strongly moderately weathered mudstone blocks and drains the underground seepage therein through the enhanced protection system. Since the composite protective structure of the present application only includes an enhanced protection system and a drainage back-pressure stabilization system, the drainage back-pressure stabilization system that plays a back-pressure stabilization role is arranged on the slope of the diseased area through the enhanced protection system, and the root of the slope of the diseased area is reinforced by the enhanced protection system, which solves the technical problem that the combination of buttress retaining walls and steel pipe piles in the prior art for dealing with slope problems requires a larger working surface, and the main load-bearing supporting structure is a buttress retaining wall. By adopting the technical solution of the present application, the enhanced protection system is combined with the drainage back-pressure stabilization system to achieve the treatment of slope diseased areas. The required construction working surface is small, and the construction operation is convenient and fast. The enhanced protection system is arranged at the root of the slope, which can significantly enhance the anti-slip ability. The drainage back-pressure stabilization system is used to compact the slope, and the project cost is significantly reduced, which is conducive to its wide promotion in the treatment of slope diseased areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of the composite protective structure used for the treatment and repair of slope diseased areas according to the present invention;

[0028] Figure 2 It is a schematic diagram of the arrangement of composite steel pipe piles along the length direction involved in the composite protective structure for treating and repairing slope diseased areas of the present invention;

[0029] Figure 3 A schematic diagram of the structure of the composite steel pipe piles and the light buttress-type cast-in-place retaining wall connected to the composite protective structure for the treatment and repair of slope disease areas;

[0030] Figure 4The present invention is a schematic diagram of the structure of the steel pipe involved in the composite protective structure for treating and repairing slope disease areas.

[0031] Marked in the figure are: strongly to moderately weathered mudstone 1, water-rich loose landslide deposit 2, access roadbed 3, drainage ditch 4, drainage back pressure stabilization system 5, retaining and draining component 6, drainage hole 7, supporting stabilization pile 8, steel pipe 9, reinforced concrete filling body 10, grouting hole 11. DETAILED DESCRIPTION

[0032] like Figure 1 , Figure 2 , Figure 3 as well as Figure 4The present invention provides a composite protective structure and construction method for the treatment and repair of slope diseased areas, which are convenient and fast to construct, have strong anti-slip ability and low engineering cost, and a construction method for the composite protective structure for the treatment and repair of slope diseased areas. The composite protective structure includes a strongly medium weathered mudstone 1 and a water-rich loose landslide accumulation 2 obliquely pressed on the strongly medium weathered mudstone slope. The composite protective structure also includes an enhanced protection system and a drainage counter-pressure stabilization system 5. The enhanced protection system is inserted into the slope at the root of the strongly medium weathered mudstone through its lower part. The drainage counter-pressure stabilization system 5 obliquely pressed on the strongly medium weathered mudstone slope blocks and drains underground seepage water therein through the enhanced protection system. The technical solution provided by the present application is based on the existing strongly moderately weathered mudstone and the water-rich loose landslide accumulation obliquely pressed on the slope of the strongly moderately weathered mudstone. The composite protection structure of the present application is formed by adding an enhanced protection system and a drainage back pressure stabilization system. The enhanced protection system is then inserted into the slope at the root of the strongly moderately weathered mudstone through its lower part, and the drainage back pressure stabilization system obliquely pressed on the slope of the strongly moderately weathered mudstone blocks and drains the underground seepage water therein through the enhanced protection system. Since the composite protective structure of the present application only includes an enhanced protection system and a drainage back-pressure stabilization system, the drainage back-pressure stabilization system that plays a back-pressure stabilization role is arranged on the slope of the diseased area through the enhanced protection system, and the root of the slope of the diseased area is reinforced by the enhanced protection system, which solves the technical problem that the combination of buttress retaining walls and steel pipe piles in the prior art for dealing with slope problems requires a larger working surface, and the main load-bearing supporting structure is a buttress retaining wall. By adopting the technical solution of the present application, the enhanced protection system is combined with the drainage back-pressure stabilization system to achieve the treatment of slope diseased areas. The required construction working surface is small, and the construction operation is convenient and fast. The enhanced protection system is arranged at the root of the slope, which can significantly enhance the anti-slip ability. The drainage back-pressure stabilization system is used to compact the slope, and the project cost is significantly reduced, which is conducive to its wide promotion in the treatment of slope diseased areas. Of course, in order to facilitate the construction of the composite protective structure, the present application also arranges a convenient roadbed 3 on the outside of the enhanced protection system, and tilts the convenient roadbed 3 at least 2% toward the side of the enhanced protection system in the width direction to avoid water accumulation in the convenient roadbed, and then at least a drainage ditch 4 is arranged at the junction of the convenient roadbed 3 and the enhanced protection system to drain the collected water on the convenient roadbed.

[0033] Accordingly, in combination with the actual situation of the construction site and the existing technology, in order to facilitate construction, reduce the working surface required for construction as much as possible, and maximize the stability of the slope after treatment, the drainage counter-pressure stabilization system 5 of the present application is a counter-pressure crushed stone filled on the side surface of the water-rich loose landslide slope in cooperation with the enhanced protection system, and the angle between the pressure-jointed surface of the counter-pressure crushed stone and the horizontal plane is between 40° and 50°. The enhanced protection system of the present application includes a lower plug-in support stabilization component and an upper retaining support drainage component 6, the upper part of the plug-in support stabilization component is embedded in the lower retaining support drainage component, and the enhanced protection system is plugged into the slope at the root of the strong and medium weathered mudstone through the plug-in support stabilization component, and at least the drainage counter-pressure stabilization system 5 is supported, drained and kept stable through the retaining support drainage component 6. More specifically, the retaining and draining assembly 6 is composed of a light buttress cast-in-place retaining wall, on which a plurality of downwardly inclined drainage holes 7 are arranged, and the flocculent seepage water and underground seepage water in the water-rich loose landslide accumulation 2 and the strong and medium weathered mudstone 1 are discharged to the outside of the light buttress cast-in-place retaining wall through the drainage back pressure stabilization system 5. The plug-in support stabilization assembly includes a plurality of support stabilization piles 8 sequentially embedded in the root slope of the strong and medium weathered mudstone along the length direction, and the upper part of each support stabilization pile 8 is embedded in the wall of the lower part of the light buttress cast-in-place retaining wall at the corresponding position.

[0034] Furthermore, in order to facilitate construction as much as possible while ensuring the management requirements and at the same time reducing the construction cost as much as possible, the present application has two rows of supporting stabilization piles 8 embedded in the root slope of strongly moderately weathered mudstone along the length direction, and the distance between two adjacent supporting stabilization piles 8 in each row of supporting stabilization piles 8 is not less than 1m, the row spacing between the two rows of supporting stabilization piles 8 is not less than 0.5m and they are staggered, the length of each supporting stabilization pile 8 inserted into the slope is not less than 5m, and the length extending out of the slope is between 2.5 and 3.5m. Each supporting stabilizing pile 8 is composed of a composite steel pipe pile, and each composite steel pipe pile is sequentially embedded in the root slope of the strongly to moderately weathered mudstone along the length direction of the slope. Specifically, each composite steel pipe pile includes three steel pipes 9 and three groups of reinforced concrete filling bodies 10. Grouting holes 11 are respectively arranged at the lower end of each steel pipe 9. Each steel pipe 9 is spot-welded into a whole through a plurality of groups of connecting steel bars arranged at intervals along its length direction. A group of reinforced concrete filling bodies 10 are respectively filled in each steel pipe 9. Each composite steel pipe pile 8 combined into a whole is filled with a fixed grouting body between the strongly to moderately weathered mudstone 1 and the outer wall of the composite steel pipe pile at the corresponding position through the grouting holes 11.

[0035] In this way, the composite protective structure of the present application can be constructed according to the following steps:

[0036] 1) Select down-the-hole drilling rigs and grouting machines according to design requirements, conduct appearance inspection and quality assurance acceptance of steel pipe piles, and level the construction site;

[0037] 2) Drilling, installing steel pipes and grouting to form steel pipe piles,

[0038] 3) After the slurry meets the specified strength requirements, a light retaining wall formwork is set up to pour the retaining wall concrete. During the pouring process, drainage holes are left layer by layer as required;

[0039] 4) After the strength of the retaining wall meets the requirements, the back of the wall is backfilled with gravel to complete the construction of the composite protective structure. The drilling, installation of steel pipes and grouting to form steel pipe piles, which are the key control processes, are carried out according to the following steps:

[0040] a. Put the drilling rig in place, measure the center point of the pile position according to the design drawing, and align the drilling rig steadily after ensuring that the hole position is correct;

[0041] b. Drilling: Use a drilling rig to drill. During the drilling process, check the ground conditions at any time to select the drilling frequency. After reaching the designed elevation, confirm with the relevant parties;

[0042] c. Steel pipe hoisting: After professional technicians weld and form the steel pipe piles in plum blossom shape, transport them to the site, hold the steel pipe and the internal steel bars firmly, and then slowly lower them to the hole. If there is any obstruction, find out the cause and correct it;

[0043] d. Slurry preparation and grouting. Prepare the slurry according to the mix ratio and use the grouting pipe to inject the slurry into the bottom of the hole. After the grouting is completed, use high-pressure water to flush the grouting pipe to prevent blockage to complete the construction work of drilling and grouting to form steel pipe piles.

[0044] In summary, the technical solution provided by the present application aims to achieve the effect of coordinated force by effectively integrating the retaining wall and the steel pipe column and optimizing the combination so that the structure can give full play to its own advantages to a greater extent. The light buttress-type cast-in-place retaining wall structure of the present application can be greatly reduced in form compared to the cross-sectional shape of the gravity retaining wall. It is in a subordinate and auxiliary position in the support system, and together with the steel pipe piles, it balances the downward sliding force or soil pressure of the slope. Due to the presence of steel pipe piles, the upper light retaining wall does not have to consider the flange requirements of the retaining wall and the bearing capacity requirements of the foundation of the retaining wall too much. Therefore, the construction of the retaining wall is different from the large-scale excavation scale of the traditional retaining wall, which greatly reduces the excavation disturbance of the slope during the construction of the retaining wall, which is beneficial to improve the stability of the slope. In particular, in the construction of the light steel pipe pile retaining wall combination system, due to the use of small machinery such as down-the-hole drills to preferentially apply steel pipe piles, it not only effectively avoids the difficulty of using large machinery to apply large-section anti-sliding piles of traditional punching piles or rotary piles, but also effectively improves the scope of use of the project. And because the upper light retaining wall is constructed after the priority construction of the steel pipe piles, the disturbance to the slope during the construction is greatly reduced. It has the advantages of small construction disturbance, convenient and fast construction, strong anti-slip ability and low project cost. It is particularly suitable for projects in which there is often insufficient working surface space in the slope disease treatment area in actual applications and large-volume retaining walls cannot be implemented. The biggest advantage of the technical solution of this application is that the retaining wall structure is in a subordinate and auxiliary position in the support system, and together with the steel pipe piles, it balances the downward force or soil pressure of the slope. Compared with the buttress retaining wall, the cross-sectional shape of the light retaining wall can be greatly reduced, and the space required for construction is only 1 / 3-1 / 4 of that of the buttress retaining wall, which greatly reduces the amount of excavation. When using small machinery such as down-the-hole drilling rigs for construction, the disturbance to the slope is small. It has the advantages of small construction disturbance, convenient and fast construction, strong anti-slip ability and low project cost.

[0045] When carrying out this slope engineering with existing technology, anti-slide piles are generally selected for support and protection. Although the use of anti-slide piles can effectively treat the disease, it is difficult to carry out the construction due to the large rotary drilling rig, and the project cost is high and the construction period is long. Therefore, considering the construction period and economy and the actual situation on site, it is more economical and reasonable to use a combination structure with light pile retaining wall as the main and steel pipe piles as the auxiliary.

[0046] A steel pipe pile light retaining wall combined protection structure is designed to ensure that the retaining structure construction has small disturbance, convenient and fast construction, strong anti-slip ability and low engineering cost.

[0047] Second, the combined structure has a small site requirement, a fast drilling speed, and the steel pipe piles that are set first have little disturbance to the slope. The retaining wall can be directly constructed on the steel pipe piles after cleaning the upper covering soil. A blind drainage ditch can be set behind the wall to effectively drain the groundwater from the slope. This solution has obvious advantages in terms of construction period and engineering cost.

[0048] The technical solution of the present application is further described below through specific embodiments:

[0049] This application designs a steel pipe pile light retaining wall combined protection structure, so that the construction of the retaining structure has the effect of small disturbance, convenient and fast construction, strong anti-slip ability and low engineering cost. The combined protection structure mainly adds steel pipe piles at the bottom of the light retaining wall as auxiliary force, and provides base bearing capacity so that the structure itself and the backfill can reach an overall supporting and stable state. It is mainly composed of three parts: the first part is the back-pressure measure behind the wall: mainly including back-pressure gravel behind the wall; the second part is the steel pipe pile force system: as an auxiliary force system in the combined structure, it includes steel pipe piles, anchor steel bars in the piles and grouting slurry; the third part is the retaining wall force system: as the main force system in the combined structure, it includes the retaining wall foundation, wall body and drainage structure.

[0050] Based on the characteristics of the landslide and the size of the sliding force, the combined structure sets up two rows of 10m long, 0.5m horizontally and 1m vertically, with a pile diameter of Φ108mm, in a plum blossom shape at the foot of the slope. The steel pipes extend out of the ground for about 2.5 to 3.5m and are buried 5 to 6m below the ground.

[0051] The first part is the back-pressure measures behind the wall: mainly including gravel behind the wall. In addition to the back-pressure effect on the slope itself, the gravel behind the wall can effectively remove the groundwater in the slope, so that the water in the original water-rich slope passes through the gravel to the wall, and then drains to the ditch through the wall drainage holes. The gravel is easy to obtain and construct, which can effectively increase the construction speed, reduce the disturbance time of the slope, and increase the safety of construction.

[0052] The second part is the steel pipe pile force system: as an auxiliary force system in the composite structure, it includes steel pipe piles, anchor steel bars in the piles and grouting slurry. Steel pipe columns are fast to construct and easy to purchase. Their horizontal setting can effectively provide anti-overturning capacity for light retaining walls, that is, the anti-pulling of the rear row of steel pipes and the anti-compression of the front row of steel pipes are used to effectively realize the anti-overturning capacity of the composite system structure. Since this engineering measure is carried out with a small down-the-hole drilling rig, it has less requirements on the site, fast drilling speed, and the preferentially set micro-piles have little disturbance on the slope. The retaining wall can be directly constructed on the micro-piles after clearing the upper covering soil, which has obvious advantages.

[0053] The third part is the retaining wall stress system: as the main stress system in the composite structure, it includes the retaining wall foundation, wall body and drainage structure. Together with the steel pipe piles, it forms a retaining stress structure. The wall body and foundation are made of C30 concrete, and the drainage holes are arranged in a plum blossom shape with a vertical and horizontal spacing of 2m.

[0054] The combination of these three parts forms a complete combined protective structure, which makes the construction of the retaining structure less disturbing, convenient and fast, with strong anti-slip ability and low project cost.

[0055] Embodiment 1

[0056] 1. According to the project requirements, select appropriate down-the-hole drilling rigs, grouting machines and other construction equipment, conduct appearance inspection and quality assurance acceptance of the steel pipe piles used in the project, and use them only after they are qualified. Level the construction site to ensure that the construction equipment can enter the site and operate smoothly;

[0057] 2. The specific construction process is:

[0058] a) Drilling rig in place: measure the center point of the pile position according to the design drawing, ensure that the hole position is correct, and align the drilling rig steadily;

[0059] b) Drilling: Use a drilling rig to drill, check the ground conditions at any time to select the drilling frequency, and after reaching the designed elevation, the relevant parties will confirm;

[0060] c) Steel pipe hanging: After the steel pipe is welded by professional technicians, it is transported to the site, and the steel pipe and the internal steel bars are aligned with the hole and slowly lowered. If there is any obstruction, the cause is found out and corrected;

[0061] d) Slurry preparation and grouting: Prepare slurry according to the mix ratio and use the grouting pipe to inject the slurry into the bottom of the hole. After grouting, use high-pressure water to flush the grouting pipe to prevent blockage;

[0062] e) After the slurry meets the strength requirements, a light retaining wall formwork is set up to pour the retaining wall concrete. Before pouring, drainage holes are left layer by layer as required;

[0063] f) After the retaining wall strength meets the requirements, gravel backfill is carried out on the back of the wall to meet the joint force requirements.

Claims

1. A composite protective structure for treating and repairing a slope diseased area, comprising a strongly moderately weathered mudstone (1) and a water-rich loose landslide deposit (2) obliquely pressed on the strongly moderately weathered mudstone slope, characterized in that: The composite protection structure also includes an enhanced protection system and a drainage counter-pressure stabilization system (5). The enhanced protection system is inserted into the slope at the root of the strong and medium weathered mudstone through its lower part. The drainage counter-pressure stabilization system (5) obliquely pressed on the strong and medium weathered mudstone slope blocks and drains the underground seepage therein through the enhanced protection system.

2. The composite protective structure for treating and repairing slope damage areas according to claim 1 is characterized in that: The access roadbed (3) is arranged outside the enhanced protection system, the access roadbed (3) is inclined at least 2% along the width direction toward one side of the enhanced protection system, and a drainage ditch (4) is provided at least at the junction of the access roadbed (3) and the enhanced protection system.

3. The composite protective structure for treating and repairing slope damage areas according to claim 1 or 2, characterized in that: The drainage back pressure stabilization system (5) is a back pressure crushed stone filled on the side surface of the water-rich loose landslide slope in cooperation with the enhanced protection system, and the angle between the back pressure crushed stone pressing surface and the horizontal plane is between 40° and 50°.

4. The composite protective structure for treating and repairing slope damage areas according to claim 3 is characterized by: The enhanced protection system comprises a lower plug-in support stabilization component and an upper retaining support and drainage component (6), wherein the upper part of the plug-in support stabilization component is embedded in the lower retaining support and drainage component, and the enhanced protection system is plugged into the slope at the root of the strongly medium weathered mudstone through the plug-in support stabilization component, and at least the drainage back pressure stabilization system (5) is supported, drained and kept stable through the retaining support and drainage component (6).

5. The composite protective structure for treating and repairing slope damage areas according to claim 4 is characterized in that: The retaining and draining assembly (6) is composed of a light buttress type cast-in-place retaining wall, on which a plurality of downwardly inclined drainage holes (7) are arranged. The flocculent seepage water and underground seepage water in the water-rich loose landslide accumulation (2) and the strongly medium-weathered mudstone (1) are discharged to the outside of the light buttress type cast-in-place retaining wall through the drainage holes (7) at corresponding positions in cooperation with the drainage back pressure stabilization system (5).

6. The composite protective structure for treating and repairing slope damage areas according to claim 5 is characterized by: The plug-in support stabilization component comprises a plurality of support stabilization piles (8) sequentially embedded in the root slope of the strong and medium weathered mudstone along the length direction, and the upper part of each support stabilization pile (8) is respectively embedded in the wall body of the lower part of the light buttress type cast-in-place retaining wall at the corresponding position.

7. The composite protective structure for treating and repairing slope damage areas according to claim 6 is characterized by: There are two rows of supporting and stabilizing piles (8) embedded in the root slope of the strongly medium weathered mudstone along the length direction. The distance between two adjacent supporting and stabilizing piles (8) in each row is not less than 1m. The row spacing between the two rows of supporting and stabilizing piles (8) is not less than 0.5m and they are staggered. The length of each supporting and stabilizing pile (8) inserted into the slope is not less than 5m, and the length protruding from the slope is between 2.5 and 3.5m.

8. The composite protective structure for treating and repairing slope damage areas according to claim 7 is characterized in that: Each supporting stabilizing pile (8) is composed of a composite steel pipe pile, and each composite steel pipe pile is sequentially embedded in the slope at the root of the strong and medium weathered mudstone along the length direction of the slope. Each composite steel pipe pile comprises three steel pipes (9) and three groups of reinforced concrete filling bodies (10). Grouting holes (11) are respectively arranged at the lower end of each steel pipe (9). Each steel pipe (9) is spot-welded into a whole through a plurality of groups of connecting steel bars arranged at intervals along the length direction thereof. Each steel pipe (9) is respectively filled with a group of reinforced concrete filling bodies (10). Each composite steel pipe pile (8) assembled into a whole is respectively filled with fixed grouting bodies between the strongly and moderately weathered mudstone (1) and the outer wall of the composite steel pipe pile at a corresponding position through the grouting holes (11).

9. The construction method for the composite protective structure for treating and repairing slope damage areas as claimed in claim 8, characterized in that: The construction method comprises the following steps: 1) Select down-the-hole drilling rigs and grouting machines according to design requirements, conduct appearance inspection and quality assurance acceptance of steel pipe piles, and level the construction site; 2) Drilling, installing steel pipes and grouting to form steel pipe piles, 3) After the slurry meets the specified strength requirements, a light retaining wall formwork is set up to pour the retaining wall concrete. During the pouring process, drainage holes are left layer by layer as required; 4) After the strength of the retaining wall meets the requirements, gravel backfill is carried out on the back of the wall to complete the construction of the composite protective structure.

10. The construction method according to claim 9, characterized in that: The drilling and grouting to form the steel pipe column is carried out in the following steps: a. Put the drilling rig in place, measure the center point of the pile position according to the design drawing, and align the drilling rig steadily after ensuring that the hole position is correct; b. Drilling: Use a drilling rig to drill. During the drilling process, check the ground conditions at any time to select the drilling frequency. After reaching the designed elevation, confirm with the relevant parties; c. Steel pipe hoisting: After professional technicians weld and form the steel pipe piles in plum blossom shape, transport them to the site, hold the steel pipe and the internal steel bars firmly, and then slowly lower them to the hole. If there is any obstruction, find out the cause and correct it; d. Slurry preparation and grouting. Prepare the slurry according to the mix ratio and use the grouting pipe to inject the slurry into the bottom of the hole. After the grouting is completed, use high-pressure water to flush the grouting pipe to prevent blockage to complete the construction work of drilling and grouting to form steel pipe piles.

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