CN-121997414-A - High and steep slope roadbed reinforcement and gravity type retaining wall combined supporting structure and design method

CN121997414ACN 121997414 ACN121997414 ACN 121997414ACN-121997414-A

Abstract

The invention discloses a combined supporting structure of a high and steep slope roadbed and a gravity type retaining wall and a design method, wherein the supporting structure comprises a embankment supporting structure and a drainage system, the embankment supporting structure comprises a gravity type retaining wall, the gravity type retaining wall is arranged on a medium-pressure slate of a slope toe, a reinforcement area is arranged above the gravity type retaining wall, the reinforcement area comprises an unmodified reinforcement area and a modified reinforcement area from inside to outside, reinforcement materials are paved in layers in the reinforcement area, a reinforcement modified soil cushion layer is horizontally paved between the bottom of the reinforcement area and the top of the gravity type retaining wall, and the reinforcement materials are paved in the reinforcement modified soil cushion layer in a full-section mode. And optimizing the length of the reinforcement and the height of the retaining wall according to different damage modes. The invention improves the overall stability of the combined structure based on the cooperative supporting effect between the modified reinforced wall and the gravity retaining wall, optimizes the length of the reinforced material and the height of the retaining wall, reduces the construction cost and realizes the dual aims of saving the cost and optimizing the engineering performance.

Inventors

LIU JIAQING
TANG ZHENGHUI
LIU JUNYI
QIU XIANG
LIAO ZUXING
YIN QIAN
CAI YIHANG
HUANG SHANGJIAN
LIU YIXUAN
SHAO YU
LIU XIANLIN

Assignees

广西新发展交通集团有限公司
长沙理工大学
广西交通设计集团有限公司

Dates

Publication Date: 20260508
Application Date: 20251230

Claims (10)

1. The combined supporting structure of the high and steep slope roadbed reinforcement and the gravity type retaining wall comprises a embankment supporting structure and a drainage system, and is characterized in that the embankment supporting structure comprises a gravity type retaining wall (6), the gravity type retaining wall (6) is arranged on a medium-impact slate (2) at the toe of a slope, a reinforcement area is arranged above the gravity type retaining wall (6), the reinforcement area comprises a non-modified reinforcement area (3) and a modified reinforcement area (4) from inside to outside, and reinforcement materials are paved in the reinforcement area in layers; The reinforced modified soil cushion layer (5) is horizontally paved between the bottom of the reinforced area and the top of the gravity type retaining wall (6), the reinforced modified soil cushion layer (5) is internally paved with reinforced materials in a full-section mode, and the reinforced materials in the reinforced modified soil cushion layer (5) are anchored in the gravity type retaining wall (6).
2. The combined supporting structure for the high and steep slope roadbed reinforcement and the gravity retaining wall is characterized in that a platform is arranged at the top of a modified reinforcement area (4), a filling layer (1) is paved outside a wind-caused slate (2) above the reinforcement area, a step structure is arranged at the wind-caused slate (2) behind the gravity retaining wall (6), and a filling layer (1) is paved in an area between the gravity retaining wall (6), the step structure of the wind-caused slate (2) and a reinforced modified soil cushion layer (5).
3. The combined supporting structure for the high and steep slope roadbed reinforcement and the gravity retaining wall is characterized in that an unmodified reinforcement area (3) is filled with plain soil in a layered mode, a modified reinforcement area (4) is filled with modified soil in a layered mode, modified soil of a reinforcement modified soil cushion layer (5) and modified soil of the modified reinforcement area (4) are the same in component, and cement and plain soil are mixed according to a mass ratio of 2:25-1:10.
4. The combined supporting structure of the high and steep slope roadbed reinforcement and the gravity retaining wall according to claim 1, wherein the drainage system comprises a longitudinal drainage ditch of a embankment slope, a continuous drainage layer and a drainage hole in front of the wall, the longitudinal drainage ditch is positioned on the surface of the embankment slope, and one longitudinal drainage ditch is arranged at fixed intervals along the embankment slope, and extends from the slope top to the slope bottom; the continuous drainage layer is positioned between the filling layer (1) and the wall back of the gravity retaining wall (6) and is filled by water seepage materials; The drainage hole before the wall is a row of PVC pipe of diameter 50~100mm, sets up in the position that is higher than embankment basement fixed distance, and outer end downward sloping, the continuous drainage layer of inner embedding, the pipe shaft parcel is strained geotechnique in the opposite directions.
5. The method for designing the combined supporting structure of the high and steep slope roadbed reinforcement and the gravity retaining wall according to claim 1, which is characterized by comprising the following steps: s1, identifying a damage mode of overall instability; S2, aiming at the mode one, a sliding surface shears off an unmodified reinforcement area (3) and a modified reinforcement area (4) and reinforcement materials are pulled out of a slope, a most dangerous sliding surface (7) is searched by software, a soil body above the most dangerous sliding surface (7) and positioned at the inner side of the reinforcement area is divided into a plurality of vertical soil strips, and unbalanced thrust transmitted by the soil strips close to the reinforcement area is calculated by adopting an unbalanced thrust method, so that the length of the reinforcement materials in the reinforcement area required by resisting the unbalanced thrust is determined; S3, aiming at the second mode, the soil body slides out from the top of the gravity retaining wall (6), and the residual sliding force under the working condition of combining the thicknesses of different reinforced modified soil cushion layers (5) and the heights of the gravity retaining wall (6) is calculated, so that the optimal combination of the thicknesses of the reinforced modified soil cushion layers (5) and the heights of the gravity retaining wall (6) is determined; S4, aiming at the third mode, the gravity type retaining wall (6) is overturned or slipped, and the anti-slip and anti-overturning stability of the gravity type retaining wall (6) are checked by establishing a X, Y-direction static equilibrium equation in consideration of the earth pressure behind the wall, the earth wedge gravity and the tension of the reinforced material transmitted by the reinforced modified earth cushion layer (5) to the gravity type retaining wall (6).
6. The method for designing a combined supporting structure of a high and steep slope roadbed reinforcement and a gravity retaining wall according to claim 5, wherein in the step S2, the calculation method of the length of the reinforcement material is as follows: S21, vertically cutting the junction point Q of the most dangerous sliding surface (7) and the reinforced area, wherein the reinforced area soil strip blocks are arranged outside the cutting line, and the inner side of the cutting line is vertically cut at equal width to obtain a plurality of soil strip blocks; s22, anti-slip force of soil strips in reinforced area Calculated according to formula (1): (1) in the formula, The area of the soil strip block in the reinforced area; Is the soil weight of the reinforced area; an included angle between the lower part of the soil strip block in the reinforced area and the horizontal direction; The internal friction angle of the soil strip block in the reinforced area; the adhesive force of the sliding surface of the soil strip block in the reinforced area; the length of the soil strip block in the reinforced area; the pulling resistance of the reinforcement material in the reinforcement area is calculated according to the pulling resistance generated by the upper surface and the lower surface of the reinforcement material according to the formula (2): (2) in the formula, Is the pulling resistance of the reinforcement; Is the vertical earth pressure above the tendon, The width of the rib material; is the length of the rib material; is the coefficient of friction; In order to balance the landslide thrust transmitted to the soil strips in the reinforced area by the soil strips in the adjacent reinforced area, the required anti-slip force of the soil strips in the reinforced area Calculated according to formula (3): (3) in the formula, Is a safety factor for the sliding down of the most dangerous sliding surface (7); The landslide thrust transmitted to the soil strip blocks in the reinforced area by the soil strip blocks in the adjacent reinforced area is calculated by an unbalanced thrust method; The length of the bar is obtained by combining the formula (1), the formula (2) and the formula (3) 。
7. The method for designing the combined supporting structure of the high and steep slope roadbed reinforcement and the gravity retaining wall according to claim 6, wherein the method for calculating the landslide thrust transmitted to the soil blocks in the reinforcement area by the soil blocks in the adjacent reinforcement area through the unbalanced thrust method is specifically as follows: (4) in the formula, Represent the first The soil strips are transferred to the first Thrust of individual soil blocks, parallel to A bottom sliding surface of each soil strip block; is a landslide safety factor; Is the first The soil strips are self-gravity; Represent the first The lower parts of the soil strips form included angles with the horizontal direction; Represent the first The length of each soil strip block; Represent the first Internal friction angles of the soil strips; Represent the first The adhesive force of the sliding surfaces of the soil strips; Represent the first The soil strips are transferred to the first Thrust of each soil strip block; Indicating the thrust from the first The soil strips are transferred to the first The transmission coefficient of each soil strip block; Transmission coefficient Calculated by formula (5): (5) in the formula, Represent the first -1 Angle between the lower part of the soil strip and the horizontal direction.
8. The method for designing the combined supporting structure of the high and steep slope roadbed reinforcement and the gravity type retaining wall according to claim 5, wherein in the step S3, the method for calculating the remaining sliding force of the combined structure of the reinforcement modified soil cushion layer (5) and the gravity type retaining wall (6) is as follows: S31, pulling resistance of the rib material And tensile resistance The smaller value of the steel bar is used as the skid resistance generated by the bar material ; S32, when the most dangerous sliding surface (7) passes through the reinforced modified soil cushion layer (5), considering the contribution of the reinforced layer, and calculating the generated sliding resistance according to the formula (6): (6) representing the slip resistance of the ith soil block; Is the first Self-gravity of each soil strip block; Represent the first The lower parts of the soil strips form included angles with the horizontal direction; Represent the first Internal friction angles of the soil strips; Represent the first The adhesive force of the sliding surfaces of the soil strips; Represent the first The length of each soil strip block; S33, calculating the residual sliding force of the counter-slope segment according to the formula (7): (7) Represent the first The soil strips are transferred to the first The thrust force of each soil strip block, Represent the first The soil strips are transferred to the first The thrust force of each soil strip block, Indicating the thrust from the first The soil strips are transferred to the first The transmission coefficient of each soil strip block, Is the first The downward sliding component of each soil strip block.
9. The method for designing a combined supporting structure of a high and steep slope roadbed reinforcement and a gravity retaining wall according to claim 8, wherein the method for determining the counter-slope section is characterized in that: taking the top point N of the wall edge of the gravity retaining wall (6) as a starting point, making an initial ray inclined downward at a fixed included angle with the horizontal direction, and intersecting the circular arc of the most dangerous sliding surface (7) at the point The reverse extension line sequentially intersects with the lower surface of the reinforced modified soil cushion layer (5) at a point Intersecting the slope surface at a point ; Taking N as a base point, rotating an initial ray once every fixed angle along the clockwise direction to generate a series of new rays which respectively intersect with the circular arc of the most dangerous sliding surface (7) at points a, b, c, d and e, and the reverse extension line intersecting with the reinforced modified soil cushion layer (5) at the points 、、、 And The slope surface of the intersecting slope is at the point 、、、 And ; Connecting the intersection point of the most dangerous sliding surface (7) and the slope surface to form a line segment 、、、 And I.e. the counter-slope segment.
10. The method for designing a combined supporting structure of a high and steep slope roadbed reinforcement and a gravity type retaining wall according to claim 8, wherein the pulling resistance of the reinforcement is calculated When the steel bar is in the anchoring section, the length of the steel bar is divided after the most dangerous sliding surface (7) passes through the steel bar.

Description

High and steep slope roadbed reinforcement and gravity type retaining wall combined supporting structure and design method Technical Field The invention belongs to the technical field of computer-aided roadbed design, and relates to a high and steep slope roadbed reinforcement and gravity type retaining wall combined supporting structure and a design method. Background With the deep promotion of the national strategy of strong traffic and the comprehensive implementation of national comprehensive three-dimensional traffic network planning outline, the forward mountain heavy-hilly area of the highway network is continuously extended, and a large number of high-steep embankment sections are formed. The prior reinforcement technology faces double challenges of stability and economy when treating the high-steep road embankment slope engineering. The construction method is mainly characterized in that ① traditional embankment filling and supporting technology is used for reinforcing the whole embankment, stress characteristics of the embankment are not reasonably utilized, so that serious unreasonable phenomena exist in the paving length of the reinforced area, resource waste is caused, engineering cost is increased, under the working condition of ② high-steep embankment, the traditional gravity retaining wall excessively relies on dead weight to resist soil pressure, the increase of wall body height causes remarkable increase of material consumption and economic efficiency is reduced, and the ③ high-steep embankment often faces engineering problems of large soil pressure, high sliding and overturning risks and the like due to large filling height and steep gradient. Therefore, a novel high-steep slope roadbed supporting structure with both safety and economy needs to be developed. The invention patent with publication number of CN110258220A discloses a method for ecologically filling road embankment by using high-strength steel wire mesh reinforced materials, which integrally reinforces the filled embankment by using the high-strength steel wire mesh, although the whole shear strength of the embankment side slope can be improved, the embankment below the road only receives the pressure of upper load, the material waste can be caused when the embankment is reinforced, and the engineering cost is increased. The invention patent with publication number CN118774169A discloses a high-filling embankment of a complex steep terrain gravity type retaining wall and a construction method, and the invention adopts a pile foundation bearing platform integrated structure, solves the stability problem of a complex steep section gravity type retaining wall foundation, improves the bearing capacity of the complex steep section gravity type retaining wall, but only considers the bearing capacity requirement of the gravity type retaining wall below 5m-6m on the steep slope embankment support, and does not fully consider the stability requirement. In summary, the existing high steep slope roadbed reinforcement method has the following problems: (1) The existing high-steep road embankment reinforcement method generally adopts an integral reinforcement strategy, is not designed differently according to the stress characteristics of different areas of the embankment, so that the material waste and the cost are increased, the laying length of the reinforcement materials is not optimized by combining with the local stability calculation result, and redundancy or deficiency is caused. (2) Under the working condition of the high and steep road embankment, the traditional gravity retaining wall excessively depends on dead weight to resist soil pressure, and the continuous increase of the height of the wall body leads to obvious increase of material consumption and reduction of economical efficiency. (3) The steep embankment is large in filling height and steep in gradient, and often faces engineering problems of large soil pressure, high sliding and overturning risks and the like. Disclosure of Invention In order to solve the problems, the invention provides a combined supporting structure of a high and steep slope roadbed reinforcement and a gravity type retaining wall, which comprises the gravity type retaining wall, a reinforcement area and a reinforcement modified soil cushion layer, and based on the cooperative supporting effect between the modified reinforcement and the gravity type retaining wall, the overall stability of the combined structure is improved, the engineering cost is reduced, and the dual aims of saving cost and optimizing engineering performance are achieved. The invention further aims to provide a design method of the combined supporting structure of the high and steep slope roadbed reinforcement and the gravity retaining wall, and the length of the reinforcement and the height of the retaining wall are optimized. The technical scheme adopted by the invention is that the combined supporting structure of the high and