A construction method for a steep slope unloading type ultra-high cantilever retaining wall structure

Abstract

A steep slope unloading type ultra-high cantilever retaining wall structure and construction method can greatly enhance the stability of the cantilever retaining wall and effectively control the horizontal deformation, and solve the technical problems of the difficulty of slope closing, stability and deformation control of ultra-high fill in steep slope areas. It includes: a cantilever retaining wall, which is set on the stable foundation rock and soil under the steep slope; fixed anchor rods, which are arranged at intervals in the foundation under the heel plate of the cantilever retaining wall and fixedly connected to the heel plate; tension anchor cables, which are arranged inside in the stable rock and soil of the steep slope; load beams, which are arranged vertically in rows and longitudinally at the same intervals along the cantilever wall of the cantilever retaining wall, the inner side of which enters a certain depth into the rock and soil of the steep slope and is fixedly connected to the tension anchor cables, and the outer side passes through the through hole on the cantilever wall of the cantilever retaining wall; fixed beam caps, which are arranged on the outer side of the cantilever wall of the cantilever retaining wall and fixedly connected to the load beams; prefabricated bearing plates, which are arranged in layers on the load beams; and fill bodies, which are filled in layers on the foundation between the cantilever retaining wall and the steep slope surface.

Description

Technical Field

[0001] The invention relates to geotechnical engineering, and in particular to a construction method of a steep slope unloading type super-high cantilever retaining wall structure. Background Art

[0002] Steep slopes are very common in mountainous areas. It is difficult to completely avoid steep slopes when constructing road projects in mountainous areas. Cantilever retaining walls have the characteristics of good slope reduction effect and low foundation bearing capacity requirements, but their use height is limited, usually not exceeding 6m. If traditional reinforcement piles are used to reduce the slope, the pressure of the super-high fill soil will be large, the length and cross-section of the reinforcement piles will be large, the investment will be high, and the construction will be difficult. In order to give full play to the advantages of cantilever retaining walls, it is of great significance to propose a cantilever structure that can adapt to the slope reduction of super-high fill, and it should have the characteristics of good stability, controllable deformation, convenient construction, good economy, environmental protection and promotion. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a construction method of a steep slope unloading type super-high cantilever retaining wall structure, so as to greatly enhance the stability of the cantilever retaining wall and effectively control the horizontal deformation, and solve the technical problems such as the difficulty in slope closing of super-high fill in steep slope areas, and the difficulty in controlling stability and deformation.

[0004] The technical solution adopted by the present invention to solve the above technical problems is as follows:

[0005] The invention discloses a method for constructing a steep slope unloading type ultra-high cantilever retaining wall structure, wherein the retaining wall structure comprises: a cantilever retaining wall, which is arranged on a stable foundation rock and soil under a steep slope, wherein the cantilever wall is provided with reserved through holes in rows at intervals along the longitudinal direction; fixed anchor rods, which are arranged at intervals in the foundation under the heel plate of the cantilever retaining wall and are fixedly connected to the heel plate; a tension anchor cable, which is arranged inside the stable rock and soil of the steep slope and outside the cantilever retaining wall and is exposed 0.3-0.5m outside the slope; a load-bearing beam, which is arranged along the cantilever retaining wall. The cantilever walls of the earth wall are arranged in vertical rows and at equal intervals, with their inner sides entering a certain depth into the steep slope rock and soil and fixedly connected with the tensioned anchor cables, and their outer sides passing through the through holes on the cantilever walls of the cantilever retaining wall; fixed beam caps are arranged on the outer sides of the cantilever walls of the cantilever retaining wall and fixedly connected with the load-bearing beams; prefabricated bearing plates are arranged in layers on the load-bearing beams, with their two ends laid on the longitudinally adjacent load-bearing beams; fill bodies are layered on the foundation between the cantilever retaining wall and the steep slope surface;.

[0006] The construction method includes the following steps:

[0007] ① Level the foundation of the cantilever retaining wall, construct fixed anchor rods at intervals on the foundation, and grout the anchor rods to stabilize them. The exposed height of the fixed anchor rods should be no less than 0.3m above the ground.

[0008] ②Construct cantilever retaining wall reinforced concrete and pre-embed PVC pipes at the through-hole positions of the cantilever wall;

[0009] ③ Drill holes on the steep slope to construct the first tension anchor cable, and reinforce it with grouting. The length of the anchor section and the free section of the tension anchor cable should not be less than 4.0m;

[0010] ④Fill the fill body in layers to the top elevation of the first load-bearing beam;

[0011] ⑤ Excavate a foundation pit for the load-bearing beam in the fill body, excavate a placement hole in the steep slope body, and construct the reinforced concrete of the load-bearing beam. The inner load-bearing steel bars of the load-bearing beam are fixedly connected with the tension anchor cable, and the outer side passes through the cantilever wall. The longitudinal load-bearing steel bars are exposed from the cantilever wall by no less than 0.3m;

[0012] ⑥Construct the fixed beam cap on the outside of the cantilever wall, and fix the beam cap steel bars with the exposed steel bars of the load-bearing beam;

[0013] ⑦Install the prefabricated bearing plate on the load-bearing beam;

[0014] ⑧Fill the fill body on the prefabricated bearing plate in layers to the top elevation of the next load-bearing beam;

[0015] ⑨ Repeat steps ③ to ⑧ until the construction of all tensioning anchor cables, load-bearing beams, fixed beam caps and fill bodies is completed.

[0016] The beneficial effect of the present invention is that the load-bearing beams and prefabricated bearing plates are arranged vertically and longitudinally at intervals on the super-high cantilever retaining wall, so that the earth pressure generated by the cantilever retaining wall can be unloaded. At the same time, the load-bearing beams can provide a large favorable pulling force for the cantilever retaining wall under the action of the inner tension anchor cable, greatly enhancing the stability of the cantilever retaining wall and effectively controlling the horizontal deformation. The load-bearing beams and the cantilever retaining wall are hinged, and no unfavorable bending moment will be generated for the cantilever retaining wall, so that the cantilever retaining wall has good economy. The fixed anchor rods can provide the cantilever retaining wall with a large bearing capacity and a large anti-slip and anti-overturning capacity, so that the cantilever retaining wall can be used for super-high filling and slope reduction; the tension anchor cable is arranged to fix the load-bearing beam, and the effective pulling force is transmitted to the cantilever retaining wall through the load-bearing beam; the fixed beam cap is used to fix the load-bearing beam, so that the force can be effectively transmitted between the load-bearing beam and the cantilever retaining wall; the prefabricated bearing plate is used for fast construction, and its function is to unload the earth pressure.

[0017] The construction method proposed by the invention is simple to operate and easy to control in quality; the construction of the filling body is not affected by the setting of the load-bearing beams; and the method has the characteristics of being economical, environmentally friendly and conducive to popularization. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] This specification includes the following drawing:

[0019] Figure 1It is a cross-sectional schematic diagram of a steep slope unloading type super-high cantilever retaining wall structure of the present invention;

[0020] The figure shows the component names and the corresponding marks: fixed anchor rod 1, cantilever retaining wall 2, tension anchor cable 3, load-bearing beam 4, fixed beam cap 5, prefabricated bearing plate 6, and fill body 7. DETAILED DESCRIPTION

[0021] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0022] Reference Figure 1 The present invention discloses a steep slope unloading type ultra-high cantilever retaining wall structure, comprising: a cantilever retaining wall 2, arranged on a stable foundation rock and soil under a steep slope, wherein the cantilever wall has reserved through holes in a row along the longitudinal direction; fixed anchor rods 1, arranged at intervals in the foundation under the heel plate of the cantilever retaining wall 2, and fixedly connected to the heel plate; a tension anchor cable 3, the inner side of which is arranged in the stable rock and soil of the steep slope, and the outer side is exposed 0.3-0.5m outside the slope; a load-bearing beam 4, which is arranged along the cantilever wall vertical direction of the cantilever retaining wall 2. They are arranged in rows and at the same intervals in the longitudinal direction, with their inner sides entering into the steep slope rock and soil to a certain depth and fixedly connected to the tension anchor cable 3, and their outer sides passing through the through holes on the cantilever wall of the cantilever retaining wall 2; fixed beam caps 5 are arranged on the outer side of the cantilever wall of the cantilever retaining wall 2 and fixedly connected to the load-bearing beams 4; prefabricated bearing plates 6 are arranged in layers on the load-bearing beams 4, and their two ends are laid on the longitudinally adjacent load-bearing beams 4; fill bodies 7 are filled in layers on the foundation between the cantilever retaining wall 2 and the steep slope surface.

[0023] Reference Figure 1 The present invention sets a load beam 4 and a prefabricated bearing plate 6 at vertical and longitudinal intervals on the super-high cantilever retaining wall 2, which can realize the unloading of the soil pressure generated by the cantilever retaining wall 2. At the same time, the load beam 4 can provide a large favorable pulling force for the cantilever retaining wall 2 under the action of the inner tension anchor cable 3, greatly enhancing the stability of the cantilever retaining wall 2 and effectively controlling the horizontal deformation. The load beam 4 is hinged with the cantilever retaining wall 2, and will not produce an unfavorable bending moment to the cantilever retaining wall 2, so that the cantilever retaining wall 2 has better economy. The fixed anchor rod 1 can provide the cantilever retaining wall 2 with a large bearing capacity and a large anti-slip and anti-overturning ability, so that the cantilever retaining wall 2 can be used for super-high filling and slope reduction. The tension anchor cable 3 can fix the load beam 4 and transmit the effective pulling force to the cantilever retaining wall 2 through the load beam 4. The fixed beam cap 5 is used to fix the load beam 4 so that the force can be effectively transmitted between it and the cantilever retaining wall 2. The prefabricated bearing plate 6 is used, which is fast to construct and its function is to unload the soil pressure.

[0024] The vertical spacing of the load-bearing beams 4 along the cantilever wall is 3-5m, and the longitudinal spacing is generally 8-10m.

[0025] Reference Figure 1 The present invention provides a method for constructing a steep slope unloading type ultra-high cantilever retaining wall structure, comprising the following steps:

[0026] ① Level the foundation of the cantilever retaining wall 2, construct fixed anchor rods 1 at intervals on the foundation, and grout the anchors to stabilize them. The exposed height of the fixed anchor rods should be no less than 0.3m above the ground;

[0027] ②Construct cantilever retaining wall 2 reinforced concrete and pre-embed PVC pipes at the through-hole positions of the cantilever wall;

[0028] ③ Drill holes on the steep slope to construct the first tension anchor cable 3, and reinforce it with grouting. The anchor section length and free section length of the tension anchor cable 3 shall not be less than 4.0m;

[0029] ④ Fill the filling body 7 in layers to the top elevation of the first load-bearing beam 4;

[0030] ⑤ Excavate the foundation pit of the load-bearing beam 4 in the fill body 7, excavate the placement hole in the steep slope body, construct the reinforced concrete of the load-bearing beam 4, the inner load-bearing steel bars of the load-bearing beam 4 are fixedly connected with the tension anchor cable 3, and the outer side passes through the cantilever wall, and the longitudinal load-bearing steel bars are exposed from the cantilever wall by no less than 0.3m;

[0031] ⑥Construct the fixed beam cap 5 on the outside of the cantilever wall, and fix the steel bars of the fixed beam cap 5 to the exposed steel bars of the load-bearing beam 4;

[0032] ⑦ Install the prefabricated bearing plate 6 on the load-bearing beam 4;

[0033] ⑧ Layered filling of the fill body 7 on the prefabricated bearing plate 6 to the top elevation of the next load-bearing beam;

[0034] ⑨ Repeat ③ to ⑧ until the construction of all tension anchor cables 3, load-bearing beams 4, fixed beam caps 5 and fill bodies 7 is completed.

[0035] The above description is only to illustrate some principles of the construction method of a steep slope unloading super-high cantilever retaining wall structure of the present invention, and is not intended to limit the present invention to the scope of application of the specific structure and construction method shown and described. Therefore, all corresponding modifications and equivalents that may be used are within the scope of the patent applied for by the present invention.

Claims

1. A method for constructing a steep slope unloading type ultra-high cantilever retaining wall structure, the retaining wall structure comprising: A cantilever retaining wall (2) is arranged on a stable foundation rock and soil under a steep slope, and the cantilever wall is provided with through holes arranged in rows at intervals along the longitudinal direction; fixed anchor rods (1) are arranged in intervals in the foundation under the heel plate of the cantilever retaining wall (2) and are fixedly connected to the heel plate; a tension anchor cable (3) is arranged inside the stable rock and soil of the steep slope and outside the cantilever retaining wall (2) and is exposed 0.3-0.5m outside the slope; a load-bearing beam (4) is arranged in rows along the cantilever wall of the cantilever retaining wall (2) and at equal intervals along the longitudinal direction, and the inner side of the tension anchor cable (3) enters the steep slope. A fixed beam cap (5) is arranged at a certain depth in the slope rock soil and is fixedly connected to the tension anchor cable (3), and the outer side passes through the through hole on the cantilever wall of the cantilever retaining wall (2); a fixed beam cap (5) is arranged on the outer side of the cantilever wall of the cantilever retaining wall (2) and is fixedly connected to the load-bearing beam (4); a prefabricated bearing plate (6) is arranged in layers on the load-bearing beam (4), and the two ends are laid on the longitudinally adjacent load-bearing beams (4); a fill body (7) is filled in layers on the foundation between the cantilever retaining wall (2) and the steep slope surface; The construction method includes the following steps: ① Level the foundation of the cantilever retaining wall (2), construct fixed anchor rods (1) at intervals on the foundation, and grout the anchor rods to stabilize them. The fixed anchor rods should be exposed above the ground by no less than 0.3m; ②Construct cantilever retaining wall (2) reinforced concrete, and pre-embed PVC pipes at the through holes set in the cantilever wall; ③ Drill holes on the steep slope to construct the first tension anchor cable (3), and reinforce it with grouting. The length of the anchor section and the free section of the tension anchor cable (3) shall not be less than 4.0 m; ④ Fill the fill body (7) in layers to the top elevation of the first load-bearing beam (4); ⑤ Excavate a foundation pit for the load-bearing beam (4) in the fill body (7), excavate a placement hole in the steep slope body, and construct the reinforced concrete of the load-bearing beam (4). The inner load-bearing steel bars of the load-bearing beam (4) are fixedly connected to the tension anchor cable (3), and the outer side passes through the cantilever wall. The longitudinal load-bearing steel bars are exposed from the cantilever wall by no less than 0.3m; ⑥ constructing a fixed beam cap (5) on the outside of the cantilever wall, and fixing the steel bars of the fixed beam cap (5) to the exposed steel bars of the load-bearing beam (4); ⑦ Installing the prefabricated bearing plate (6) on the load-bearing beam (4); ⑧ Layered filling of the fill body (7) on the prefabricated bearing plate (6) to the top elevation of the next load-bearing beam; ⑨ Repeat steps ③ to ⑧ until the construction of all tension anchor cables (3), load-bearing beams (4), fixed beam caps (5) and fill bodies (7) is completed.

2. The method for constructing a steep slope unloading type super-high cantilever retaining wall structure as claimed in claim 1, characterized in that: The load-bearing beams (4) are arranged at a vertical spacing of 3-5 m along the cantilever wall, and are generally arranged at a longitudinal spacing of 8-10 m.

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