A method for constructing anti-sliding structure of high fill slope

Abstract

The present invention relates to a method for constructing an anti-sliding structure for a high fill slope, including arranging a multi-layer drainage steel cage in the fill area and connecting and anchoring it with an anti-sliding pier in the original soil or rock layer according to the mechanism that the shear strength of the high fill slope is reduced by the infiltration of rainstorm and flood into the soil body and the scouring of water flow, so as to achieve the dual functions of draining the water in the soil body and balancing the horizontal thrust of the soil body in the fill area; the anti-sliding wall at the bottom of the slope and the concrete-cast bottom plate form a "T-shaped" slope foot structure to improve the anti-overturning ability of the anti-sliding wall; introducing the safety factor of shallow landslide in the fill area and the safety factor of deep landslide that penetrates the fill area and the original soil area, respectively verifying the anti-sliding stability of the shallow local and deep layers of the slope. The beneficial effects of the present invention are: reducing uneven settlement of the fill foundation, surface cracks and surface rainwater infiltration, preventing the development of potential landslide surfaces, ensuring the stability of high slopes in extreme rainstorm weather, and compared with the commonly used arc sliding method, the force mechanism is clearer and the calculation method is simpler.

Description

Technical Field

[0001] The invention relates to the technical field of construction and traffic engineering, and in particular to a method for constructing a high-slope anti-slip structure of a fill. Background Art

[0002] In extreme weather conditions, heavy rain and precipitation increase dramatically, mountain torrents occur, and large-scale landslides are very likely to occur on the high slopes of mountain highway fills and construction sites.

[0003] For high fill slopes, lattice ground beams + anchor support are usually used for reinforcement. Arc arch stone retaining wall support, or reinforced earth retaining walls, wire mesh flexible retaining structures, anti-slip piles, buttress retaining walls, micro anti-slip piles, etc. are also used. The drainage method is to insert plastic drainage pipes with a length of only 1.0m~2.0m at intervals of about 2.0m on the slope surface to drain water. It can only drain the surface water of the slope, but not the deep water. Hemp silk and geotextiles are placed at the contact point between the drainage pipe and the soil to isolate the mud and sand. After a few years, the possibility of plastic drainage pipes being blocked increases, and the shear strength of the soil soaked by the accumulated water decreases, thus leading to landslides. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a method for constructing an anti-slip structure for a high fill slope, which can solve the problem that conventional slope retaining wall structures only have drainage pipes on the surface and cannot solve the problem of deep drainage in the fill area. It can improve the anti-overturning ability of the high fill slope, reduce the risk of shallow and deep landslides, and ensure the stability of the high slope in extreme rainstorm weather.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] A method for constructing a high fill slope anti-sliding structure, comprising:

[0007] The filling area and the original soil area of ​​the high slope are repaired together with the slope surface, and the surface vegetation layer and loose soil are excavated. The step width meets the requirements of the anti-sliding pier construction working surface;

[0008] Build a drainage ditch at the foot of the excavation area at the top of the high slope to intercept the water collected at the top of the fill area;

[0009] Anti-slip piers are constructed on the steps, and their strength and rigidity meet the stability requirements;

[0010] Construct anti-slip walls and drainage ditches at the foot of the fill area at the bottom of the high slope;

[0011] Remove vegetation and soft soil under the anti-slip wall bottom plate, level the site, pour the cushion layer, tie the bottom plate longitudinal steel bars and bottom plate transverse steel bars, weld the embedded horizontal steel bars in the anti-slip wall at the bottom plate elevation to the bottom plate longitudinal steel bars, pour the bottom plate concrete, so that the anti-slip wall and the concrete poured bottom plate form a "T" shape structure;

[0012] The backfill area is backfilled in layers from the bottom plate to the top of the slope. Each backfilled layer of soil is then repeatedly vibrated and compacted. When the backfill height of each layer of soil reaches the laying position of the drainage steel cage, the drainage steel cage is laid on the soil layer according to the designed spacing of the drainage steel cage, and the longitudinal stress-bearing steel bars, angle steels, and cross bracing steel plates of the anti-sliding pier exposed on the top of the anti-sliding pier are all inserted into the drainage steel cage to form the anchoring end of the drainage steel cage, and then the drainage steel cage is anchored to balance the horizontal thrust of the soil. The longitudinal stress-bearing steel bars of the drainage steel cage and the longitudinal stress-bearing steel bars, angle steels, and cross bracing steel plates of the anti-sliding pier exposed on the top of the anti-sliding pier are all coated with epoxy resin;

[0013] Construct a slope drainage ditch on the outside of the high slope top, and construct a drainage ditch on the slope surface of the high slope; if the slope top surface is a construction site, cast a concrete surface layer to seal it; if the slope top surface is a highway pavement, treat it according to the requirements for highway roadbed and pavement.

[0014] Lay the frame concrete panels on the high slope surface, drive dowels into the four corners of each frame concrete panel to fix it, and then plant slope protection vegetation inside the frame concrete panel;

[0015] Carry out stability verification on the anti-sliding structure construction of high fill slope.

[0016] Furthermore, the stability verification of the anti-sliding structure construction of the fill high slope includes:

[0017] The design value of the horizontal tension of a single drainage steel cage is calculated according to the formula Calculate, where The number of longitudinal stress-bearing steel bars of a single drainage steel cage; is the cross-sectional area of ​​the longitudinal stress-bearing steel bar of a single drainage steel cage, in mm 2 ; It is the tensile strength of the longitudinal reinforcement of the drainage reinforcement cage, in kN / mm 2 ;

[0018] The anti-sliding force provided by a single drainage steel cage to the fill layer is calculated according to the formula Calculate, where is the circumference of the drainage steel cage, in m; is the length of the drainage steel cage, in m; is the characteristic value of the friction resistance of the drainage steel cage to the fill layer, in kPa; , the drainage steel cage will not be broken when there is a landslide tendency;

[0019] The sum of the characteristic values ​​of the horizontal bearing capacity of the anti-sliding pier is calculated according to the formula Calculate, where is the total number of anti-slide piers in the potential shallow landslide area; is the characteristic value of the horizontal bearing capacity of the anti-sliding pier (4), which is determined through a horizontal bearing capacity test or according to the formula Estimated, among which is the diameter of the anti-sliding pier, in m; is the soil pressure in the active area of ​​the anti-sliding pier, in kPa; is the soil pressure in the passive zone of the anti-sliding pier, in kPa; It is the difference between the height of the anti-sliding pier and the height of the active earth pressure zone of the anti-sliding pier, in meters; is the height of the active earth pressure zone of the anti-sliding pier, in m;

[0020] The horizontal safety factor of shallow landslide stability is calculated according to the formula Verification, where is the number of drainage steel cages within the potential shallow landslide mass; is the vertical projection area of ​​the potential shallow landslide, unit: m 2 ; is the active earth pressure coefficient; is the weight of the fill, in kN / m 3 ; is the thickness of the potential shallow landslide mass, in m; ≥1.1;

[0021] The vertical safety factor of shallow landslides satisfies the requirement that the bearing capacity of the composite foundation of drainage steel cage and high-compacted fill of the same standard is greater than the deadweight of the upper fill layer;

[0022] The overall stability safety factor of the anti-slide wall and bottom plate of deep landslide is calculated according to the formula Calculate, where is the soil pressure in the active area of ​​the anti-sliding wall, in kPa; is the soil pressure in the passive zone of the anti-sliding wall, in kPa; is the characteristic value of the frictional resistance between the bottom plate and the original soil under the bottom plate, in kPa; is the residual horizontal thrust of the deep potential sliding surface, in kN; B is the width of the anti-sliding wall and the bottom plate, in m; is the overhang height of the anti-slip wall, in m; is the embedding depth of the anti-slip wall, in m; is the length of the base plate, in m; ≥1.1;

[0023] The vertical safety factor of deep landslides satisfies the requirement that the bearing capacity of the original soil under the bottom plate is greater than the deadweight of the upper fill layers transferred to the bottom plate.

[0024] Furthermore, when constructing the anti-slip pier, the longitudinal force-bearing steel bars of the anti-slip pier are exposed from the top surface of the anti-slip pier, and no less than 4 angle steels are inserted into the top surface of the anti-slip pier. The angle steels are connected and fixed by cross-braced steel plates to strengthen the lateral stiffness. The depth of the angle steel inserted into the concrete of the anti-slip pier is not less than 0.5m. The diameter of the anti-slip pier is 300mm~1000mm, and the spacing is 2000mm~5000mm.

[0025] Furthermore, when constructing anti-slip walls and anti-slip piers, the embedding depth of the anti-slip walls and anti-slip piers penetrates the deep sliding surface and is embedded in the hard soil layer by not less than 4.0m, or embedded in the strongly weathered rock layer by not less than 3.0m, or embedded in the moderately weathered rock layer by not less than 2.0m.

[0026] Furthermore, the infiltration end of the drainage steel cage is filled with anti-corrosion fiber fabric, the middle part of the drainage steel cage is filled with graded sand and gravel, and the drainage end of the drainage steel cage is installed with a fine wire mesh graded sand and gravel cage.

[0027] Furthermore, the horizontal laying spacing and vertical laying spacing of the drainage steel cage are determined by the permeability coefficient of the backfill soil. The horizontal laying spacing of the drainage steel cage is 2000mm~5000mm from low to high according to the permeability coefficient of the backfill soil. The cross-section of the drainage steel cage is circular or rectangular. When the cross-section of the drainage steel cage is circular, the diameter of the drainage steel cage is 300mm~600mm. When the cross-section of the drainage steel cage is rectangular, the width of the drainage steel cage is 300mm~600mm.

[0028] Furthermore, the drainage steel cage is set with a drainage slope of not less than 0.2% in a manner of high inside and low outside.

[0029] Furthermore, a siphon drain pipe is arranged between the fine wire mesh graded sand and gravel cage and the drainage ditch; the water inlet of the siphon drain pipe is inserted into the fine wire mesh graded sand and gravel cage, and the drainage outlet of the siphon drain pipe is led out from the drainage ditch; the height difference between the water inlet and the drainage outlet of the siphon drain pipe is greater than the water level height of the water flowing back from the drainage ditch to the siphon drain pipe, so as to prevent the backflow of slope water.

[0030] Furthermore, the frame concrete panel is square, the length and width of the frame concrete panel are both 1000mm~2000mm, and the thickness is 30mm~50mm; a plurality of single-layer reinforcement grids made of steel wire or iron wire with a diameter of 2mm~5mm are arranged in the frame concrete panel, and the length and width of each reinforcement grid are both 100mm~500mm.

[0031] Furthermore, the high fill slope consists of a three-dimensional drainage system consisting of drainage steel cages, intercepting ditches, drainage ditches at the top of the slope, drainage ditches at the foot of the slope and discharge ditches. The cross-sectional width of the intercepting ditch is not less than 500mm~1000mm, and the cross-sectional depth is not less than 600mm~1500mm; the spacing of the discharge ditches is consistent with the spacing of the drainage steel cages, the cross-sectional width of the discharge ditches is not less than 200mm~300mm, and the cross-sectional depth is not less than 100mm~200mm; the cross-sectional width of the drainage ditch at the top of the slope and the drainage ditch at the foot of the slope are both not less than 500mm~800mm, and the cross-sectional depth is both not less than 400mm~600mm.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] 1. The present invention sets up multi-layer drainage steel cages in the high slope filling area, so that when the rainstorm flood infiltrates from the surface into the ground, it is discharged from the deep to the slope surface through the steel cage connected to the siphon drainage pipe to the drainage ditch. The siphon drainage pipe prevents the water in the drainage ditch from flowing back into the drainage pipe, and drains the underground water in time to ensure that the shear strength of the soil is not reduced. The drainage steel cage has high tensile strength and will not be broken by the horizontal tensile force, causing landslides.

[0034] 2. The present invention excavates the interface between the fill area and the original soil into a stepped serrated shape, and arranges a row of steel cages at a certain height along the depth direction. The main bars of the steel cages play a dual role of horizontal tensile resistance and vertically improving the bearing capacity of the fill foundation, solving the problems of uneven settlement of the foundation in the fill area and shallow landslides, and the graded sand and gravel play a drainage role; the anti-slip piers connected to the main bars of the steel cages are driven into the original hard soil or rock layer, and play an anti-slip role on the high slopes in layers and sections, avoiding the risk of overall landslides caused by the overturning of the anti-slip piers usually set at the foot of the slope.

[0035] 3. In the present invention, the anti-slip wall and the base plate are connected to form a rigid whole. The "T"-shaped structure increases horizontal support compared to traditional anti-slip piles and increases embedding depth compared to buttress retaining walls. The base plate with two-way reinforcement has higher foundation bearing capacity and resistance to uneven settlement than replacement foundations.

[0036] 4. The present invention introduces the safety factor of shallow landslide in the fill area and the safety factor of deep landslide that runs through the fill area and the original soil area, and calculates the horizontal and vertical safety factors respectively. Compared with the commonly used arc sliding method, the force mechanism and calculation method are simple and clear, which improves the anti-sliding safety of high slopes in the fill area. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of the landslide cross section of the high slope excavation area and the filling area in the present invention;

[0038] Figure 2 It is a schematic cross-sectional view of the anti-sliding structure of the high slope filling area of ​​the present invention;

[0039] Figure 3 It is a schematic diagram of the connection between the drainage steel cage and the anti-sliding pier in the present invention;

[0040] Figure 4 It is a schematic elevation view of the welding of the longitudinal stress-bearing steel bars and the angle steel of the anti-sliding pier at the top of the anti-sliding pier in the present invention;

[0041] Figure 5 It is a schematic diagram of the welding cross section of the longitudinal stress-bearing steel bars and angle steels at the top of the anti-sliding pier pile in the present invention;

[0042] Figure 6 It is an enlarged schematic diagram of the steel bar connection between the anti-slip wall and the bottom plate in the present invention;

[0043] Figure 7 It is a structural schematic diagram of the drainage steel cage in the present invention;

[0044] Figure 8 It is a schematic diagram of the structure of the fine wire mesh graded sand and stone cage in the present invention;

[0045] Fig. 9 for Figure 2 A schematic diagram of the structure enlargement at point A;

[0046] Fig.10 It is a schematic elevation diagram of the high slope filling area in the present invention;

[0047] Fig.11 It is a schematic diagram of assembling the lattice concrete panel of the present invention;

[0048] Fig.12 This is a schematic diagram of planting slope protection vegetation in the present invention;

[0049] Fig.13 It is a schematic diagram of the force analysis of the drainage steel cage and the anti-sliding pier in the present invention;

[0050] Fig.14 It is a schematic diagram of the force analysis of the anti-slip wall and the bottom plate in the present invention.

[0051] In the figure: 1. Original soil area combined with slope surface; 101. Excavation area; 102. Filling area; 103. Intercepting ditch; 104. Drainage ditch on top of slope; 2. Anti-slip wall; 201. Longitudinal reinforcement of anti-slip wall; 202. Bottom plate; 203. Longitudinal reinforcement of bottom plate; 3. Drainage reinforcement cage; 301. Anti-corrosion fiber fabric; 302. Graded sand and gravel; 303. Fine wire mesh graded sand and gravel cage; 304. Siphon drainage pipe; 4. Anti-slip pier; 401. Longitudinal force reinforcement of anti-slip pier; 402. Concrete; 403. Angle steel; 404. Cross braced steel plate; 5. Frame concrete panel; 501. Inserted reinforcement; 502. Slope protection vegetation; 6. Drainage ditch; 7. Drainage ditch at the foot of slope; 801. Shallow potential sliding surface; 802. Middle potential sliding surface; 803. Deep potential sliding surface. DETAILED DESCRIPTION

[0052] The present invention is further described below in conjunction with the accompanying drawings, but the protection scope of the present invention is not limited to the following description.

[0053] like Figure 1-12 As shown, a method for constructing an anti-sliding structure for a fill high slope includes the following construction steps:

[0054] like Figure 1 As shown, the filling area 102 and the original soil area of ​​the high slope are repaired in combination with the slope surface 1, and the surface vegetation layer and loose soil are excavated. The step width meets the requirements of the construction working surface of the anti-sliding pier 4.

[0055] like Figure 2 As shown, a drainage ditch 103 is built at the foot of the excavation area 101 at the top of the high slope. The drainage ditch 103 cuts off the hillside water flow and drains it from the periphery of the filling area 102.

[0056] like Figure 2 As shown, an anti-slip pier 4 is constructed on the zigzag step. The anti-slip pier 4 can be a steel pipe, a prefabricated pier or a cast-in-place pier. The insertion depth of the anti-slip pier 4 should meet the anti-slip stability requirements.

[0057] like Figure 2 As shown, an anti-slip wall 2 and a drainage ditch 7 are constructed at the foot of the fill area 102 at the bottom of the high slope.

[0058] like Figure 2 , Figure 6 As shown, the vegetation and soft soil under the bottom plate 202 of the anti-slip wall 2 are excavated to expose the hard original soil, the site is leveled, and the cushion layer is poured, and then the bottom plate longitudinal steel bars 203 and the bottom plate transverse steel bars are tied, and the embedded horizontal steel bars in the anti-slip wall 2 at the elevation of the bottom plate 202 are welded to the bottom plate longitudinal steel bars 203, and the bottom plate concrete is poured, so that the anti-slip wall 2 and the concrete poured bottom plate 202 form a "T" shape structure.

[0059] like Figure 2-Figure 5As shown, the backfill area 102 is backfilled in layers from the bottom plate 202 to the top of the slope, with a layer thickness of 300mm~500mm. Each backfill layer of soil is then repeatedly vibrated and compacted by a rolling device. When the backfill height of each layer of soil reaches the laying position of the drainage steel cage 3, the drainage steel cage 3 is laid on the soil according to the design spacing of the drainage steel cage 3, and the longitudinal stress-bearing steel bars 401, angle steel 403, and cross bracing steel plates 404 exposed on the top of the anti-sliding pier 4 are all inserted into the drainage steel cage 3 to anchor the drainage steel cage 3 and strengthen the lateral stiffness. The longitudinal stress-bearing steel bars of the drainage steel cage and the longitudinal stress-bearing steel bars 401, angle steel 403, and cross bracing steel plates 404 exposed on the top of the anti-sliding pier 4 are all coated with epoxy resin for rust prevention. After being buried in the soil, they are isolated from the air to prevent the stress-bearing steel bars from rusting.

[0060] like Figure 2 , Fig. 9 As shown, a slope top drainage ditch 104 is constructed on the outside of the slope top of the high side slope, and a drainage ditch 6 is constructed on the slope surface of the high side slope; if the slope top surface is a construction site, a concrete surface layer is poured to seal it; if the slope top surface is a highway pavement, it is processed according to the requirements of the highway roadbed and pavement.

[0061] like Figure 2 , Fig.10 , Fig.11 , Fig.12 As shown, a lattice concrete panel 5 is laid on the high slope surface, and dowel bars 501 are driven into the four corners of each lattice concrete panel 5 for fixing, and then slope protection vegetation 502 is planted in the lattice concrete panel 5.

[0062] Through the above construction method, the bottom plate 202, the drainage steel cage 3, the anti-sliding pier 4, the frame concrete panel 5, the slope top drainage ditch 104, the slope foot drainage ditch 7, the drainage ditch 6, etc. constitute the anti-sliding structure of the filling area 102.

[0063] like Figure 4 , 5 As shown, when constructing the anti-slip pier 4, the longitudinal force-bearing steel bars 401 of the anti-slip pier are exposed from the top of the anti-slip pier 4, and no less than 4 angle steels 403 are inserted into the top of the anti-slip pier 4. The angle steels 403 are connected and fixed by cross bracing steel plates 404 to strengthen the lateral stiffness. The depth of the angle steels 403 inserted into the concrete 402 of the anti-slip pier 4 is not less than 0.5m. The diameter of the anti-slip pier 4 is 300mm~1000mm, and the spacing is 2000mm~5000mm.

[0064] When constructing the anti-slip wall 2 and the anti-slip pier 4, the embedding depth of the anti-slip wall 2 and the anti-slip pier 4 passes through the deep sliding surface and is embedded in the hard soil layer for not less than 4.0m, or embedded in the strongly weathered rock layer for not less than 3.0m, or embedded in the moderately weathered rock layer for not less than 2.0m.

[0065] Among them, the longitudinal reinforcement 203 of the bottom plate is tensile and bending reinforcement, and the transverse reinforcement of the bottom plate is distributed reinforcement; the longitudinal reinforcement 201 of the anti-sliding wall is bending reinforcement, and the transverse reinforcement of the anti-sliding wall is distributed reinforcement. By connecting the anti-sliding wall 2 and the bottom plate 202 into a rigid whole, the horizontal support is increased compared with the traditional anti-sliding piles, and the embedding depth is increased compared with the buttress retaining wall. The bottom plate 202 with two-way reinforcement has a higher foundation bearing capacity and anti-uneven settlement ability than the replacement foundation.

[0066] like Figure 7 , 8 As shown, the infiltration end of the drainage steel cage 3 is filled with anti-corrosion fiber fabric 301 to filter fine particles in the soil; the middle of the drainage steel cage 3 is filled with graded sand and gravel 302 for drainage; the drainage end of the drainage steel cage 3 is installed with a fine wire mesh graded sand and gravel cage 303 to prevent water flow from eroding the surrounding soil and causing local cavity collapse.

[0067] The horizontal laying spacing and vertical laying spacing of the drainage steel cage 3 are determined by the permeability coefficient of the backfill soil, wherein the horizontal laying spacing of the drainage steel cage 3 is 2000mm~5000mm from low to high according to the permeability coefficient of the backfill soil. Specifically, when the permeability coefficient of the backfill soil is high, the horizontal laying spacing takes a large value, and when the permeability coefficient of the backfill soil is low, the horizontal laying spacing takes a small value. The cross-section of the drainage steel cage 3 is circular or rectangular. When the cross-section of the drainage steel cage 3 is circular, the diameter of the drainage steel cage 3 is 300mm~600mm, and when the cross-section of the drainage steel cage 3 is rectangular, the width of the drainage steel cage 3 is 300mm~600mm. The drainage steel cage 3 is set with a drainage slope of not less than 0.2% in a manner of high inside and low outside to facilitate drainage.

[0068] like Fig. 9 As shown, a siphon drain pipe 304 is arranged between the fine wire mesh graded sand and gravel cage 303 and the drain ditch 6; the water inlet of the siphon drain pipe 304 is inserted into the fine wire mesh graded sand and gravel cage 303, and the drain outlet of the siphon drain pipe 304 is led out from the drain ditch 6; the height difference between the water inlet and the drain outlet of the siphon drain pipe 304 is greater than the water level height flowing back from the drain ditch 6 to the siphon drain pipe 304.

[0069] The drainage steel cage 3 plays two roles: one is to drain the accumulated water that has infiltrated the soil and keep the shear strength of the soil from decreasing; the other is to bear the horizontal thrust of the soil that may cause landslides by the longitudinal force-bearing steel bars of the drainage steel cage. Through the multi-layer drainage steel cage 3, when the rainstorm flood infiltrates from the surface into the ground, it is discharged from the deep to the slope surface through the steel cage connected siphon drainage pipe 304 to the drainage ditch 6. The siphon drainage pipe 304 can prevent the water in the drainage ditch 6 from flowing back into the drainage pipe, drain the underground water in time, and ensure that the shear strength of the soil is not reduced. In addition, the drainage steel cage 3 has a high tensile strength and will not be broken by the horizontal tensile force, causing landslides.

[0070] The frame concrete panel 5 is square, the length and width of the frame concrete panel 5 are both 1000mm~2000mm, and the thickness is 30mm~50mm; a plurality of single-layer reinforcement grids made of steel wire or iron wire with a diameter of 2mm~5mm are arranged in the frame concrete panel 5, and the length and width of each reinforcement grid are both 100mm~500mm.

[0071] The high fill slope is composed of a three-dimensional drainage system consisting of a drainage steel cage 3, an intercepting ditch 103, a slope top drainage ditch 104, a slope foot drainage ditch 7 and a drainage ditch 6. The cross-sectional dimensions of the intercepting ditch 103 are determined by the catchment area of ​​the upper hillside and the maximum rainfall, and the cross-sectional width of the intercepting ditch 103 is not less than 500mm~1000mm, and the cross-sectional depth is not less than 600mm~1500mm; the spacing of the drainage ditch 6 is consistent with the spacing of the drainage steel cage 3, and the cross-sectional width of the drainage ditch 6 is not less than 200mm~300mm, and the cross-sectional depth is not less than 100mm~200mm; the cross-sectional widths of the slope top drainage ditch 104 and the slope foot drainage ditch 7 are not less than 500mm~800mm, and the cross-sectional depths are not less than 400mm~600mm.

[0072] like Figure 2 , 13 As shown in Figures 14, the entire landslide body of the fill area 102 has a shallow potential sliding surface 801, a middle potential sliding surface 802 and a deep potential sliding surface 803. In order to ensure that the design parameters of the drainage steel cage 3, the anti-sliding pier 4, the anti-sliding wall 2 and the bottom plate 202 meet the local and overall anti-sliding stability requirements of the fill high slope, it is necessary to perform stability verification on the anti-sliding structure construction of the fill high slope. The specific verification includes:

[0073] By formula Calculate the horizontal tension design value of a single drainage steel cage 3 , where is the number of longitudinal stress-bearing steel bars of a single drainage steel cage 3; is the cross-sectional area of ​​the longitudinal stress-bearing steel bar of a single drainage steel cage, in mm 2 ; is the tensile strength of the longitudinal reinforcement of the drainage reinforcement cage, in kN / mm 2 ;

[0074] The anti-sliding force provided by a single drainage steel cage 3 to the fill layer By formula Calculate, where is the perimeter of the drainage steel cage 3, in m; is the length of the drainage steel cage 3, in m; is the characteristic value of friction resistance of drainage steel cage 3 to fill layer, unit is kPa; , the drainage steel cage 3 is not broken when there is a landslide tendency;

[0075] like Fig.13 As shown, according to the formula Calculate the sum of the characteristic values ​​of the horizontal bearing capacity of the anti-sliding pier 4 in kN, where: is the total number of anti-slide piers 4 in the potential shallow landslide area; is the characteristic value of the horizontal bearing capacity of the anti-sliding pier 4, in kN, determined by the horizontal bearing capacity test or by the formula Estimated, among which is the diameter of the anti-sliding pier 4, in m; is the earth pressure in the active area of ​​the anti-sliding pier 4, in kPa; is the earth pressure in the passive zone of the anti-sliding pier 4, in kPa; is the difference between the height of the anti-sliding pier 4 and the height of the active earth pressure zone of the anti-sliding pier 4, in meters; is the height of the active earth pressure zone of the anti-sliding pier 4, in m;

[0076] The horizontal safety factor of shallow landslide stability is calculated according to the formula Verification, ≥1.1, where is the number of drainage steel cages 3 within the potential shallow landslide body, is the vertical projection area of ​​the potential shallow landslide, unit: m 2 ; is the active earth pressure coefficient; is the weight of the fill, in kN / m 3 ; is the thickness of the potential shallow landslide mass, in m;

[0077] The vertical safety factor of shallow landslide satisfies that the bearing capacity of the composite foundation of drainage steel cage 3 and high-compacted fill of the same standard is greater than the deadweight of the upper fill layer;

[0078] like Fig.14 As shown, the overall stability safety factor of the anti-slide wall 2 and the bottom plate 202 of the deep landslide is calculated according to the formula calculate, ≥1.1, where is the earth pressure in the active area of ​​the anti-slide wall 2, in kPa; is the earth pressure in the passive zone of the anti-slide wall 2, in kPa; is the characteristic value of the frictional resistance between the bottom plate 202 and the original soil mass under the bottom plate 202, in kPa; is the residual horizontal thrust of the deep potential sliding surface, in kN; B is the width of the anti-sliding wall 2 and the bottom plate 202, in m; is the cantilever height of the anti-slip wall 2, in m; is the embedding depth of the anti-slip wall 2, in m; is the length of the bottom plate 202, in m;

[0079] The vertical safety factor of the deep landslide satisfies that the bearing capacity of the original soil under the bottom plate 202 is greater than the deadweight of the upper filling layers transferred to the bottom plate 202 .

[0080] The above verification method introduces the safety factor of shallow landslides in the fill area 102 and the safety factor of deep landslides that penetrate the fill area 102 and the original soil area, and calculates the horizontal and vertical safety factors separately. Compared with the commonly used arc sliding method, the force mechanism and calculation method are simple and clear, which improves the anti-sliding safety of the high slope in the fill area 102.

[0081] According to the mechanism that the shear strength of the high slope of the fill is reduced by the infiltration of rainstorm and mountain flood into the soil and the scouring of water flow, an anti-slip structure is constructed in the fill area 102, including horizontally arranging a plurality of layers of through-length drainage steel cages 3 in the fill area 102, the drainage steel cages 3 are anchored by anti-slip piers 4, the drainage steel cages 3 drain the water from the deep to the surface soil without taking away the silt in the soil, so that the shear strength of the soil is not reduced, and the longitudinal force-bearing steel bars of the drainage steel cage play a dual role of horizontal tensile resistance and vertically improving the bearing capacity of the fill foundation , which can solve the problems of uneven settlement of the foundation and shallow landslides in the fill area 102; the anti-slip pier 4 connected to the longitudinal force-bearing steel bars of the drainage steel cage is driven into the original hard soil or rock layer, which can play an anti-slip role on the high slope in layers and sections, avoiding the risk of overall landslide caused by the overturning of the anti-slip piles usually set at the foot of the slope; the bottom plate 202 of the fill high slope is rigidly connected to the anti-slip wall 2, which can improve the base's ability to resist uneven settlement and the fill high slope's ability to resist overturning, reduce the risk of shallow and deep landslides, and ensure the stability of the high slope even in extreme rainstorm weather.

[0082] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for constructing an anti-sliding structure for a high fill slope, characterized in that: include: The filling area (102) and the original soil area of ​​the high slope are repaired in combination with the slope surface (1), and the surface vegetation layer and loose soil are removed. The step width meets the requirements of the anti-sliding pier (4) construction working surface; A drainage ditch (103) is built at the foot of the excavation area (101) at the top of the high slope; Constructing anti-slip piers (4) on the steps; Constructing an anti-slip wall (2) and a drainage ditch (7) at the foot of the slope in the fill area (102) at the bottom of the high slope; Excavating vegetation and soft soil under the bottom plate (202) of the anti-slip wall (2), leveling the site, pouring the cushion layer, tying the bottom plate longitudinal steel bars (203) and the bottom plate transverse steel bars, welding the pre-buried horizontal steel bars in the anti-slip wall (2) at the elevation of the bottom plate (202) to the bottom plate longitudinal steel bars (203), and pouring the bottom plate concrete; The backfill area (102) is backfilled with earth in layers from the bottom plate (202) to the top of the slope, and each backfilled layer of earth is then repeatedly vibrated and compacted. When the backfill height of each layer of earth reaches the laying position of the drainage steel cage (3), the drainage steel cage (3) is laid on the earth according to the laying design spacing of the drainage steel cage (3), and the longitudinal stress-bearing steel bars (401), angle steel (403), and cross bracing steel plates (404) of the anti-sliding pier exposed on the top of the anti-sliding pier (4) are all inserted into the drainage steel cage (3) to form the anchoring end of the drainage steel cage (3), and the longitudinal stress-bearing steel bars of the drainage steel cage (3) and the longitudinal stress-bearing steel bars (401), angle steel (403), and cross bracing steel plates (404) of the anti-sliding pier exposed on the top of the anti-sliding pier (4) are all coated with epoxy resin; A slope top drainage ditch (104) is constructed on the outside of the slope top of the high side slope, and a drainage ditch (6) is constructed on the slope surface of the high side slope, wherein the spacing of the drainage ditch (6) is equal to the spacing of the drainage steel cage (3); if the slope top surface is a construction site, a concrete surface layer is poured to seal it; if the slope top surface is a highway pavement, it is treated according to the requirements for highway roadbed and pavement; Laying a frame concrete panel (5) on the surface of the high slope of the fill, driving dowel bars (501) into the four corners of each frame concrete panel (5) for fixing, and then planting slope protection vegetation (502) in the frame concrete panel (5); The stability calculation of the anti-sliding structure of the fill high slope is carried out, and the stability calculation includes: The horizontal safety factor of shallow landslide stability is calculated according to the formula Verification, where is the number of drainage steel cages (3) within the potential shallow landslide mass; The anti-sliding force provided by a single drainage steel cage (3) to the fill layer; is the total number of anti-slide piers (4) in the potential shallow landslide area; is the characteristic value of the horizontal bearing capacity of the anti-sliding pier (4); is the vertical projection area of ​​the potential shallow landslide, unit: m 2 ; is the active earth pressure coefficient; is the weight of the fill, in kN / m 3 ; is the thickness of the potential shallow landslide mass, in m; ≥1.1; The vertical safety factor of the shallow landslide satisfies the requirement that the bearing capacity of the composite foundation of the drainage steel cage (3) and the same standard high-compacted fill is greater than the deadweight of the upper fill layer; The overall stability safety factor of the anti-slide wall (2) and the bottom plate (202) of the deep landslide is calculated according to the formula Calculate, where is the soil pressure in the active area of ​​the anti-sliding wall (2), in kPa; is the soil pressure in the passive zone of the anti-sliding wall (2), in kPa; is the characteristic value of the frictional resistance between the bottom plate (202) and the original soil under the bottom plate (202), in kPa; is the residual horizontal thrust of the deep potential sliding surface, in kN; B is the width of the anti-sliding wall (2) and the bottom plate (202), in m; is the cantilever height of the anti-slip wall (2), in m; is the embedding depth of the anti-slip wall (2), in m; is the length of the bottom plate (202), in m; ≥1.1; The vertical safety factor of the deep landslide satisfies the requirement that the bearing capacity of the original soil foundation under the bottom plate (202) is greater than the deadweight of each upper filling layer transferred to the bottom plate (202).

2. The method for constructing an anti-sliding structure for a high fill slope according to claim 1, characterized in that: The stability verification of anti-sliding structure construction of fill high slope also includes: Design value of horizontal tension of a single drainage steel cage (3) By formula Calculate, where is the number of longitudinal stress-bearing steel bars of a single drainage steel cage (3); is the cross-sectional area of ​​the longitudinal stress-bearing steel bar of a single drainage steel cage, in mm 2 ; It is the tensile strength of the longitudinal reinforcement of the drainage reinforcement cage, in kN / mm 2 ; The anti-sliding force provided by a single drainage steel cage (3) to the fill layer is given by the formula Calculate, where is the circumference of the drainage steel cage (3), in m; is the length of the drainage steel cage (3), in m; is the characteristic value of the friction resistance of the drainage steel cage (3) to the fill layer, in kPa; , the drainage steel cage (3) will not be broken when there is a landslide tendency; The sum of the characteristic values ​​of the horizontal bearing capacity of the anti-sliding pier (4) is calculated according to the formula Calculate, where is the total number of anti-slide piers (4) in the potential landslide area; is the characteristic value of the horizontal bearing capacity of the anti-sliding pier (4), which is determined through a horizontal bearing capacity test or according to the formula Estimated, among which is the diameter of the anti-sliding pier (4), in m; is the soil pressure in the active area of ​​the anti-sliding pier (4), in kPa; is the soil pressure in the passive zone of the anti-sliding pier (4), in kPa; is the difference between the height of the anti-sliding pier (4) and the height of the active earth pressure zone of the anti-sliding pier (4), in meters; is the height of the active earth pressure zone of the anti-sliding pier (4), in meters.

3. The method for constructing an anti-sliding structure for a fill high slope according to claim 1, characterized in that: The longitudinal force-bearing steel bars (401) of the anti-sliding pier are exposed from the top surface of the anti-sliding pier (4), and no less than four angle steels (403) are inserted from the top of the anti-sliding pier (4). The angle steels (403) are connected by cross bracing steel plates (404) to strengthen the lateral rigidity. The depth of the angle steels (403) inserted into the concrete (402) of the anti-sliding pier (4) is not less than 0.5m. The diameter of the anti-sliding pier (4) is 300mm~1000mm, and the spacing is 2000mm~5000mm.

4. The method for constructing an anti-sliding structure for a fill high slope according to claim 1, characterized in that: The embedding depth of the anti-sliding wall (2) and the anti-sliding pier (4) penetrates the deep sliding surface and is embedded in the hard soil layer by not less than 4.0 m, or embedded in the strongly weathered rock layer by not less than 3.0 m, or embedded in the moderately weathered rock layer by not less than 2.0 m.

5. The method for constructing an anti-sliding structure for a fill high slope according to claim 1, characterized in that: The infiltration end of the drainage steel cage (3) is filled with anti-corrosion fiber fabric (301), the middle part of the drainage steel cage (3) is filled with graded sand and gravel (302), and the drainage end of the drainage steel cage (3) is installed with a fine wire mesh graded sand and gravel cage (303).

6. The method for constructing an anti-sliding structure for a high fill slope according to claim 1, characterized in that: The horizontal laying spacing and vertical laying spacing of the drainage steel cage (3) are determined by the permeability coefficient of the backfill soil. The horizontal laying spacing of the drainage steel cage (3) is 2000 mm to 5000 mm from low to high according to the permeability coefficient of the backfill soil. The cross section of the drainage steel cage (3) is circular or rectangular. When the cross section of the drainage steel cage (3) is circular, the diameter of the drainage steel cage (3) is 300 mm to 600 mm. When the cross section of the drainage steel cage (3) is rectangular, the width of the drainage steel cage (3) is 300 mm to 600 mm.

7. The method for constructing an anti-sliding structure for a fill high slope according to claim 1, characterized in that: The drainage steel cage (3) is set with a drainage slope of not less than 0.2% in a manner of high inside and low outside.

8. The method for constructing an anti-sliding structure for a high fill slope according to claim 5, characterized in that: A siphon drainage pipe (304) is arranged between the fine wire mesh graded sand and gravel cage (303) and the drainage ditch (6); the water inlet of the siphon drainage pipe (304) is inserted into the fine wire mesh graded sand and gravel cage (303), and the drainage outlet of the siphon drainage pipe (304) is led out from the drainage ditch (6); the height difference between the water inlet and the drainage outlet of the siphon drainage pipe (304) is greater than the water level of water flowing back from the drainage ditch (6) to the siphon drainage pipe (304), so as to prevent the slope drainage from flowing back into the drainage steel cage (3).

9. The method for constructing an anti-sliding structure for a high fill slope according to claim 1, characterized in that: The frame concrete panel (5) is directly laid on the fill slope surface. The frame concrete panel (5) is square. The length and width of the frame concrete panel (5) are both 1000 mm to 2000 mm, and the thickness is 30 mm to 50 mm. A plurality of single-layer reinforcement grids made of steel wires or iron wires with a diameter of 2 mm to 5 mm are arranged in the frame concrete panel (5). The length and width of each reinforcement grid are both 100 mm to 500 mm.

10. The method for constructing an anti-sliding structure for a high fill slope according to claim 1, characterized in that: The high fill slope is composed of a drainage steel cage (3), an intercepting ditch (103), a slope top drainage ditch (104), a slope foot drainage ditch (7) and a drainage ditch (6) to form a three-dimensional drainage system. The intercepting ditch (103) has a cross-sectional width of not less than 500 mm to 1000 mm and a cross-sectional depth of not less than 600 mm to 1500 mm. The spacing of the drainage ditch (6) is consistent with the spacing of the drainage steel cage (3). The cross-sectional width of the drainage ditch (6) is not less than 200 mm to 300 mm and the cross-sectional depth is not less than 100 mm to 200 mm. The cross-sectional widths of the slope top drainage ditch (104) and the slope foot drainage ditch (7) are both not less than 500 mm to 800 mm and the cross-sectional depths are both not less than 400 mm to 600 mm.

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