Slope anti-seismic structure for enhancing stability of deep-layer sliding body by manually arranging shallow-layer controllable sliding body and construction method

Abstract

The invention discloses a side slope anti-seismic measure and a design method which ensure that an artificial shallow layer sliding surface slides firstly and enhance the stability of a deep layer sliding body when a great earthquake occurs by manually arranging a shallow layer controllable sliding body. According to the method, a planar shallow sliding surface is artificially preset, a weak interface material is laid, and a buffer platform is arranged, so that an artificial shallow sliding body has a controllable sliding trend under the action of an earthquake. Under the action of an earthquake, when the artificial shallow sliding body slides along the artificial preset sliding surface, the transmission of the upper earthquake inertia force to the deep sliding body can be effectively blocked, so that the earthquake gliding force on the deep sliding surface is obviously reduced. According to the mechanical transmission mechanism, the critical condition of sliding of the deep sliding body under the action of an earthquake is obviously improved, and the overall stability of the side slope under the action of a strong earthquake is enhanced.

Description

A slope seismic-resistant structure and construction method that enhances the stability of deep landslides by artificially creating shallow, controllable landslide bodies. Technical Field

[0001] This invention belongs to the field of earthquake geotechnical engineering and slope stability control technology, specifically relating to a slope seismic-resistant structure and construction method that enhances the stability of deep sliding bodies by artificially setting shallow controllable sliding bodies. Background Technology

[0002] In mountainous transportation, engineering construction, and related geological environments, sliding surfaces are often distributed at different depths. Among them, sliding surfaces located at deeper levels, once they undergo significant deformation or overall instability, are prone to triggering large-scale landslides, leading to road interruptions, facility damage, and severe loss of life and property. Their hazards are far greater than those of sliding surfaces located at shallower levels. Therefore, the anti-sliding stability of sliding masses with deep sliding surfaces is a key control factor in slope disaster prevention.

[0003] Currently, conventional reinforcement methods for deep potential slip surfaces mainly include direct anti-slip structures, such as anti-slip piles and anchored anti-slip piles, which resist slippage by directly providing anti-slip force. The shortcomings of existing technologies are: firstly, due to the depth of the reinforcement area and the complexity of the stress mechanism, large-scale anti-slip structures are generally required for support to provide sufficient anti-slip resistance. When the maximum depth of the slip surface is large (e.g., exceeding 30m), the cost of the support structure far exceeds that when the slip surface depth is shallow, and it also places higher demands on support technology and equipment, making construction extremely difficult. Secondly, the existing anti-slide pile reinforcement system is mainly designed based on static conditions, but seismic loads have dynamic, cyclical and non-uniform characteristics, which poses multiple challenges to the seismic resistance of anti-slide piles: on the one hand, seismic loads may cause dynamic softening of the soil and rock, and may also cause the pile-soil interface to separate and the soil around the pile to crack, thereby weakening the actual reinforcement effect of the anti-slide piles; on the other hand, deep sliding surface landslides are often severely damaged after the earthquake, with complex sliding surface structures and deep locations, making post-earthquake repair extremely difficult, and even making effective repair impossible.

[0004] Therefore, there is a lack of existing technologies for reinforcing and resisting slopes with deep sliding surfaces that can reduce construction costs, improve construction operability, and provide good seismic resistance. Summary of the Invention

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a slope seismic-resistant structure that enhances the stability of deep sliding bodies by artificially setting shallow controllable sliding bodies, comprising the following components to achieve slope seismic resistance: a deep sliding body, wherein the deep sliding body is the slope body itself, which is an existing slope to be reinforced for seismic resistance, and a potential deep sliding surface exists within it; the meaning of the potential deep sliding surface is: when the unreinforced slope body encounters an earthquake alone, the shear stress at the depth of the slope body exceeds the shear strength of the slope body, thereby forming a continuous sliding surface, causing the slope body to undergo permanent deformation along the continuous sliding surface and undergo overall shear failure; an artificial weak cushion layer, artificially laid on the top surface of the deep sliding body, made of a material whose friction and sliding capacity are both less than the surrounding soil. The structure is planar in shape; the artificial weak cushion layer is used to form a defined artificial sliding surface with a shear strength lower than that of the surrounding slope soil; a buffer platform, which is set together with the artificial weak cushion layer on the top surface of the deep sliding body and located at the front end of the artificial weak cushion layer, is used to receive the soil deposited after the artificial shallow sliding body slides at its rear end, wherein the front end and the rear end are distinguished along the direction of soil sliding; the width of the buffer platform is determined according to the volume of soil sliding and the sliding displacement of the artificial shallow sliding body; a platform retaining dike is set at the front end of the buffer platform to intercept the soil sliding down at the rear end; the artificial shallow sliding body is the fill slope formed by continuing to fill on the artificial weak cushion layer, which is physically separated from the deep sliding body by the artificial weak cushion layer.

[0006] Preferably, when setting up the artificial sliding surface, the yield coefficient and sliding displacement of the potential deep sliding surface and the artificial sliding surface are calculated by inputting construction parameters. These construction parameters include: the vertical height from the bottom to the top of the artificial sliding surface, the inclination angle of the artificial sliding surface, the cohesion of the artificial sliding surface, the internal friction angle of the artificial sliding surface, and the weight of the artificial shallow sliding surface. By adjusting the construction parameters, the yield coefficient of the artificial sliding surface is made smaller than that of the potential deep sliding surface, ensuring that both the artificial shallow and deep sliding surfaces remain stable under normal working conditions and minor earthquakes. Defined; the small earthquake refers to an earthquake insufficient to trigger shear deformation of the artificial shallow sliding body along the artificial sliding surface; the calculation method of yield coefficient and sliding displacement includes the following steps: the subscripts "1" and "2" are used to distinguish between artificial shallow sliding bodies and deep sliding bodies, where subscript "1" represents the relevant parameters of the artificial shallow sliding body and subscript "2" represents the relevant parameters of the deep sliding body; α is the angle between the sliding surface and the horizontal plane, when the subscript of α is 1, the sliding surface is an artificial sliding surface, and when the subscript of α is 2, the sliding surface is a potential deep sliding surface; k h ρ is the horizontal seismic motion coefficient, N is the normal force at the bottom of the slider, T is the tangential anti-slip force at the bottom of the slider, m is the mass of the sliding body, W is the weight of the sliding body, γ is the weight of the sliding body, V is the volume of the sliding body, a is the sliding acceleration of the slider, s is the sliding displacement of the slider, g is the gravitational acceleration, and the direction of the seismic motion is horizontal. First, a force analysis is performed on the artificial shallow sliding body, and the analysis process is as follows: Horizontal force equilibrium equation: Vertical force equilibrium equation: By combining (1) and (2), we can obtain the expressions for the bottom normal force N1 and the tangential anti-slip force T1 of the artificial shallow sliding body; Sliding force T1 of artificial shallow sliding body s The anti-slip force T1 exerted by the artificial shallow sliding body is equal in magnitude and opposite in direction, and its expression is as follows: Using the Mohr-Coulomb criterion, the sliding force T1 of the artificial shallow sliding body is... s Ultimate anti-skid force T1 of artificial shallow sliding body f Subtracting them, we get equation (6): Where c1 is the cohesion of the artificial shallow landslide soil and rock mass, φ1 is the internal friction angle of the artificial shallow landslide soil and rock mass, and l1 is the length of the artificial shallow sliding surface; then, the force analysis of the deep landslide is performed, and the analysis process is as follows; the force balance equation in the horizontal direction is: Vertical force equilibrium equation: By combining (7) and (8), we can obtain the expressions for the bottom normal force N2 and the tangential anti-slip force T2 of the deep sliding body; The sliding force T2 of the deep sliding body s The anti-slip force T2 exerted by the deep sliding body is equal in magnitude and opposite in direction, and its expression is as follows: Using the Mohr-Coulomb criterion, the sliding force T2 of the deep sliding body is... s With the ultimate anti-skid force T2 of deep sliding body f Subtracting them, we get equation (12): Where c2 is the cohesion of the deep sliding body rock and soil, φ2 is the internal friction angle of the deep sliding body rock and soil, and l2 is the length of the deep sliding surface; when the sliding force T1 of the artificial shallow sliding body... s Less than the ultimate anti-skid force T1 of the artificial shallow sliding body f When the artificial shallow sliding body is in a stable state, a1=a2=0. Combining equation (6), we can obtain the conditions for the artificial shallow sliding body to slide under seismic load, that is: when the seismic action does not reach the critical threshold for shear slip of the artificial sliding surface, the artificial shallow sliding body will remain in a stable state. Where: k y1The yield coefficient of the artificial shallow sliding body is m1 = γ1V1 / g; when the sliding force T2 of the deep sliding body is... s Less than the ultimate anti-slip force T2 of the deep sliding body f When the deep sliding body is in a stable state, a1=a2=0. Combining equation (12), we can obtain the condition for the deep sliding body to slide under seismic load, that is: when the seismic action does not reach the critical threshold for the potential deep sliding surface to undergo shear slip, the deep sliding body will remain in a stable state. Where: k y2 Let m2 be the yield coefficient of the deep sliding body, and m2 = γ2V2 / g. Preferably, during a major earthquake, the artificial shallow sliding surface is ensured to slide first, and the displacement of the deep sliding body after the artificial sliding surface is installed is reduced by 50% or more compared to the displacement of the deep sliding body before the artificial sliding surface is installed, thereby achieving the protective effect on the deep sliding body. The major earthquake refers to an earthquake sufficient to trigger overall deformation of the slope along the potential deep sliding surface. In the case where the artificial shallow sliding body slides but the deep sliding body does not slide, the sliding force T2 of the deep sliding body is... s Less than the ultimate anti-slip force T2 of the deep sliding body f When the sliding acceleration a2 of the deep sliding body is 0, the anti-slip force of the artificial shallow sliding body is fully utilized, T1 s =T1 f Combining equations (6) and (12), we can obtain the critical threshold for shear slippage of deep sliding bodies under seismic load when artificial shallow sliding bodies slide. Equation (15) shows that under large earthquakes, when artificial shallow sliding bodies exist and slide, the conditions for deep sliding bodies to slide are improved compared to when no artificial shallow sliding bodies are present, i.e., k y21 >k y2 ; Where: k y21 Let A1 be the yield coefficient of the deep sliding body under the condition of artificial shallow sliding body sliding; A2 = sinα1tanφ1 + cosα1, A2 = sinα2tanφ2 + cosα2, B2 = cosα2tanφ2 - sinα2; Furthermore, in a large earthquake, when both the artificial shallow and deep sliding bodies slide, the ultimate resistance of the artificial sliding surface and the deep potential sliding surface is fully utilized, T1 s =T1 f T2 s =T2 f Combining equations (6) and (12), we can obtain the sliding acceleration of different sliding bodies; the expression for the sliding acceleration a1 of an artificial shallow sliding body is: The expression for the sliding acceleration a2 of a deep sliding body: By performing double numerical integration on the accelerations (16) and (17) of the slider throughout the entire earthquake motion, the sliding displacements of different sliding bodies along the sliding surface during the entire earthquake phase can be calculated: Where: t is the duration of the ground motion; by adjusting the construction parameters, it is ensured that under the condition of a major earthquake, the calculated displacement of the deep sliding body is reduced by 50% or more compared with the displacement before setting the artificial sliding body, and the seismic stability requirements are met.

[0007] The present invention also provides a construction method for seismic protection of deep landslides using the above-mentioned slope seismic structure, including the following steps: S1, top surface finishing of the deep landslide: fill construction is carried out according to the design slope until the design elevation of the buffer platform is reached, and the filling and compaction of the top surface of the deep landslide is completed; S2, construction of the artificial soft cushion layer: in the preset area of ​​the top surface of the deep landslide, according to the optimal design parameters determined by formula (13), including the vertical height from the bottom to the top of the artificial sliding surface, the inclination angle of the artificial sliding surface, the cohesion of the artificial sliding surface, and the internal friction angle of the artificial sliding surface, a cushion material with a shear strength less than that of the surrounding soil is evenly laid to form a continuous artificial soft cushion layer, and a connection surface with the buffer platform is reserved at its front end; S3, construction of the buffer platform: at the front end of the artificial soft cushion layer and at the top of the slope of the deep landslide, a buffer platform is constructed according to the designed volume of the artificial shallow landslide and the expected sliding displacement calculated by formula (18) when encountering a major earthquake. S4. Construction of the platform retaining dike: A long strip-shaped low dike-like passive retaining structure is set at the front end of the buffer platform. The material is mainly concrete, masonry or soil-rock mixture. It is used to intercept the soil and loose debris of the upper sliding body and prevent it from spreading downwards. S5. Construction of the artificial shallow sliding body: On the artificial soft cushion layer, according to the optimal design parameters determined by formula (13), including the vertical height of the bottom of the artificial sliding surface from the top, the inclination angle of the artificial sliding surface, the cohesion of the artificial sliding surface, the internal friction angle of the artificial sliding surface, and the optimal artificial shallow sliding body weight determined by the mass and volume of the artificial shallow sliding body in formula (13), the filling construction is carried out until a complete slope design outline is formed. This part constitutes the artificial shallow sliding body and is physically separated from the deep sliding body by the artificial soft cushion layer. S6. Construction of the slope: The final protection project is carried out on the slope of the deep sliding body and the artificial shallow sliding body.

[0008] The present invention also provides the application of the above-mentioned slope seismic-resistant structure or construction method in slope seismic resistance.

[0009] Beneficial Effects 1. By artificially setting up shallow, controllable sliding bodies to compensate for the sliding of deep sliding bodies, the stability and seismic resistance of deep sliding bodies are enhanced, avoiding the economic waste and high difficulty associated with reinforcing deep sliding surfaces. This invention eliminates the need to reinforce the potential sliding surface of the original slope. It fully utilizes the dynamic coupling effect between the two during earthquakes and their potential beneficial effect on deep stability. The shallow sliding body has a smaller burial depth, making it easier to control its design parameters and sliding deformation. By reasonably controlling the preset sliding surface and setting up a buffer platform, the shallow sliding body can form a controllable sliding trend under seismic action. This sliding process affects the transmission of seismic inertial forces in the deep slope, thus affecting the stability of the deep sliding surface. Compared with traditional direct slope reinforcement methods such as anchor cable reinforcement, the solution of this invention has higher construction controllability and better seismic resistance.

[0010] 2. This invention realizes a transformation in earthquake resistance concepts: from "passively resisting overall damage" to "actively guiding localized controllable damage to preserve the whole," establishing a new earthquake resistance paradigm of graded energy dissipation.

[0011] Theoretical analysis shows that under seismic action, when the shallow slip body slides along the artificial shallow slip surface first, it will hinder the downward transmission of its seismic inertial force, resulting in a significant reduction in the seismic sliding force at the deep potential slip surface. This significantly increases the critical condition for the deep slip body to slide, making it less likely to experience overall instability during strong earthquakes.

[0012] 3. This invention avoids the need for "full-body reinforcement" of the entire massive slope, resulting in a more cost-effective approach. If damage occurs after an earthquake, the main repair work will be concentrated on the area above the buffer platform, with clear repair objectives and a smaller workload.

[0013] 4. When setting the shape of the artificial soft cushion layer, the present invention found through calculation that, by controlling the construction parameters, the planar artificial sliding surface can meet the seismic requirements compared to the curved sliding surface. Therefore, the planar artificial sliding surface, which is easier to construct and has higher parameter control accuracy, is selected to reduce the construction difficulty and simplify the design of the cushion layer parameters. Attached Figure Description

[0014] Figure 1 is a schematic diagram of the slope structure described in this invention, which enhances the stability of deep landslides by artificially setting shallow controllable landslides.

[0015] Figure 2 is a schematic diagram of the force analysis of the sliding body in the double sliding surface system of the present invention.

[0016] Figure 3 is a schematic diagram of an example model of the dual-slip surface system of the present invention.

[0017] Figure 4 is a schematic diagram of the shallow sliding body displacement in the double sliding surface system of Embodiment 4 of the present invention.

[0018] Figure 5 is a schematic diagram comparing the displacement of the deep sliding body in the single-layer and double-layer sliding surface systems of Embodiment 4 of the present invention.

[0019] Explanation of reference numerals in the attached diagram: 1-Potential deep sliding surface; 2-Deep sliding body; 3-Artificial weak cushion layer; 4-Buffer platform; 5-Platform retaining dike; 6-Artificial shallow sliding body The following detailed description, in conjunction with the accompanying drawings and specific embodiments, provides a further detailed explanation of the slope seismic resistance measures and design method of the present invention, which enhances the stability of deep sliding masses by artificially setting shallow controllable sliding bodies.

[0020] Example 1, as shown in Figure 1, describes a slope seismic-resistant structure that enhances the stability of deep sliding bodies by artificially creating shallow controllable sliding bodies. This structure comprises the following components to achieve slope seismic resistance: a deep sliding body, which is the slope itself, an existing slope requiring seismic reinforcement, containing a potential deep sliding surface; the meaning of the potential deep sliding surface: when the unreinforced slope itself encounters an earthquake alone, the shear stress at the depth of the slope exceeds the shear strength of the slope itself, thus forming a continuous sliding surface, causing permanent deformation and overall shear failure along the continuous sliding surface; and an artificial soft cushion layer, artificially laid on the top surface of the deep sliding body, composed of a material with lower friction and sliding capacity than the surrounding soil. The structure is planar; the artificial weak cushion layer is used to form a defined artificial sliding surface with a shear strength lower than that of the surrounding slope soil; the buffer platform, together with the artificial weak cushion layer, is set on the top surface of the deep sliding body and located at the front end of the artificial weak cushion layer, used to receive the soil deposited after the artificial shallow sliding body slides at its rear end, wherein the front end and rear end are distinguished along the direction of soil sliding; the width of the buffer platform is determined according to the volume of soil sliding and the sliding displacement of the artificial shallow sliding body; the platform retaining dike is set at the front end of the buffer platform, used to intercept the soil sliding down at the rear end; the artificial shallow sliding body is the fill slope formed by continuing to fill on the artificial weak cushion layer, which is physically separated from the deep sliding body by the artificial weak cushion layer.

[0021] Example 2: As shown in Figure 2, in the slope seismic structure, when setting up the artificial sliding surface, the yield coefficient and sliding displacement of the potential deep sliding surface and the artificial sliding surface are calculated by inputting construction parameters. These construction parameters include: the vertical height from the bottom to the top of the artificial sliding surface, the inclination angle of the artificial sliding surface, the cohesion of the artificial sliding surface, the internal friction angle of the artificial sliding surface, and the weight of the artificial shallow sliding surface. By adjusting the construction parameters, the yield coefficient of the artificial sliding surface is made smaller than that of the potential deep sliding surface. Under normal working conditions and minor earthquakes, this ensures that the artificial shallow sliding body is in close contact with the deep sliding surface. All sliding bodies remain stable; the term "small earthquake" refers to an earthquake insufficient to trigger shear deformation of the artificial shallow sliding body along the artificial sliding surface; the calculation method for yield coefficient and sliding displacement includes the following steps: subscripts "1" and "2" are used to distinguish between artificial shallow and deep sliding bodies, where subscript "1" represents relevant parameters of the artificial shallow sliding body and subscript "2" represents relevant parameters of the deep sliding body; α is the angle between the sliding surface and the horizontal plane; when subscript α is 1, the sliding surface is an artificial sliding surface; when subscript α is 2, the sliding surface is a potential deep sliding surface; k h Let N be the horizontal seismic motion coefficient, N be the normal force at the bottom of the slider, T be the tangential anti-slip force at the bottom of the slider, m be the mass of the sliding body, W be the weight of the sliding body, ρ be the weight of the sliding body, V be the volume of the sliding body, a be the sliding acceleration of the slider, s be the sliding displacement of the slider, and g be the gravitational acceleration. The direction of the seismic motion is horizontal. First, the force analysis of the artificial shallow sliding body is performed. The analysis process is as follows: Horizontal force equilibrium equation: Vertical force equilibrium equation: By combining (1) and (2), we can obtain the expressions for the bottom normal force N1 and the tangential anti-slip force T1 of the artificial shallow sliding body; Sliding force T1 of artificial shallow sliding body s The anti-slip force T1 exerted by the artificial shallow sliding body is equal in magnitude and opposite in direction, and its expression is as follows: Using the Mohr-Coulomb criterion, the sliding force T1 of the artificial shallow sliding body is... s Ultimate anti-skid force T1 of artificial shallow sliding body f Subtracting them, we get equation (6): Where c1 is the cohesion of the artificial shallow landslide soil and rock mass, φ1 is the internal friction angle of the artificial shallow landslide soil and rock mass, and l1 is the length of the artificial shallow sliding surface; then, the force analysis of the deep landslide is performed, and the analysis process is as follows; the force balance equation in the horizontal direction is: Vertical force equilibrium equation: By combining (7) and (8), we can obtain the expressions for the bottom normal force N2 and the tangential anti-slip force T2 of the deep sliding body; The sliding force T2 of the deep sliding body s The anti-slip force T2 exerted by the deep sliding body is equal in magnitude and opposite in direction, and its expression is as follows: Using the Mohr-Coulomb criterion, the sliding force T2 of the deep sliding body is... s With the ultimate anti-skid force T2 of deep sliding body f Subtracting them, we get equation (12): Where c2 is the cohesion of the deep sliding body rock and soil, φ2 is the internal friction angle of the deep sliding body rock and soil, and l2 is the length of the deep sliding surface; when the sliding force T1 of the artificial shallow sliding body... s Less than the ultimate anti-skid force T1 of the artificial shallow sliding body f When the artificial shallow sliding body is in a stable state, a1=a2=0. Combining equation (6), we can obtain the conditions for the artificial shallow sliding body to slide under seismic load, that is: when the seismic action does not reach the critical threshold for shear slip of the artificial sliding surface, the artificial shallow sliding body will remain in a stable state. Where: k y1 The yield coefficient of the artificial shallow sliding body is m1 = γ1V1 / g; when the sliding force T2 of the deep sliding body is... s Less than the ultimate anti-slip force T2 of the deep sliding body f When the deep sliding body is in a stable state, a1=a2=0. Combining equation (12), we can obtain the condition for the deep sliding body to slide under seismic load, that is: when the seismic action does not reach the critical threshold for the potential deep sliding surface to undergo shear slip, the deep sliding body will remain in a stable state. Where: k y2 ρ is the yield coefficient of the deep sliding body, m2=γ2V2 / g.

[0022] Example 3, as shown in Figure 2, describes a slope seismic-resistant structure that, during a major earthquake, ensures that the artificial shallow sliding surface slides first, and reduces the displacement of the deep sliding body after the artificial sliding surface is installed by 50% or more compared to the displacement of the deep sliding body before the artificial sliding surface is installed, thereby achieving a protective effect on the deep sliding body. The major earthquake refers to an earthquake sufficient to trigger overall deformation of the slope along the potential deep sliding surface. In the case where the artificial shallow sliding body slides but the deep sliding body does not slide, the sliding force T2 of the deep sliding body... s Less than the ultimate anti-slip force T2 of the deep sliding body f When the sliding acceleration a2 of the deep sliding body is 0, the anti-slip force of the artificial shallow sliding body is fully utilized, T1 s =T1f Combining equations (6) and (12), we can obtain the critical threshold for shear slippage of deep sliding bodies under seismic load when artificial shallow sliding bodies slide. Equation (15) shows that under large earthquakes, when artificial shallow sliding bodies exist and slide, the conditions for deep sliding bodies to slide are improved compared to when no artificial shallow sliding bodies are present, i.e., k y21 >k y2 ; Where: k y21 Let A1 be the yield coefficient of the deep sliding body under the condition of artificial shallow sliding body sliding; A2 = sinα1tanφ1 + cosα1, A2 = sinα2tanφ2 + cosα2, B2 = cosα2tanφ2 - sinα2; Furthermore, in a large earthquake, when both the artificial shallow and deep sliding bodies slide, the ultimate resistance of the artificial sliding surface and the deep potential sliding surface is fully utilized, T1 s =T1 f T2 s =T2 f Combining equations (6) and (12), we can obtain the sliding acceleration of different sliding bodies; the expression for the sliding acceleration a1 of an artificial shallow sliding body is: The expression for the sliding acceleration a2 of a deep sliding body: By performing double numerical integration on the accelerations (16) and (17) of the slider throughout the entire earthquake motion, the sliding displacements of different sliding bodies along the sliding surface during the entire earthquake phase can be calculated: Where: t is the duration of the ground motion; by adjusting the construction parameters, it is ensured that under the condition of a major earthquake, the calculated displacement of the deep sliding body is reduced by 50% or more compared with the displacement before setting the artificial sliding body, and the seismic stability requirements are met.

[0023] Example 4 uses the double-slip surface sliding model shown in Figure 3 and the sinusoidal seismic wave in Figure 4 as examples. The model has a slope inclination angle of 40°, a potential deep slip surface inclination angle of 20°, a vertical height of 40 m from the bottom to the top of the potential deep slip surface, a cohesion of 26 kPa at the potential deep slip surface, and an internal friction angle of 34° at the potential deep slip surface. The artificial slip surface has an inclination angle of 8°, a vertical height of 10 m from the bottom to the top of the artificial slip surface, a cohesion of 10 kPa at the artificial slip surface, and an internal friction angle of 18° at the artificial slip surface. The weight of both the artificial shallow slip body and the deep slip body is 23 kN / m. 3 .

[0024] Based on the proposed calculation method, the yield coefficients k of the artificial shallow sliding body and the deep sliding body were calculated using formulas (13) and (14), respectively. y1 =0.28, k y2 =0.34, and further calculated the yield coefficient k of the deep sliding body when the artificial shallow sliding body slips first using formula (15). y21 =0.36. Comparative analysis shows that the yield coefficient in the latter case is higher than that when only deep sliding bodies slide. This indicates that during seismic action, the initial sliding of artificial shallow sliding bodies can hinder the downward transmission of their seismic inertial forces, thereby significantly reducing the seismic sliding force at the deep sliding surface and significantly increasing the critical condition for deep sliding bodies to slide.

[0025] Subsequently, the sliding acceleration of the artificial shallow and deep sliding bodies under two working conditions during the seismic motion was calculated using formulas (16) and (17). The corresponding sliding displacements were obtained by double numerical integration of the full-time acceleration of the artificial shallow and deep sliding bodies using formulas (18) and (19). As shown in Figures 4 and 5, after implementing shallow slip control measures, the relative displacement of the shallow sliding surface caused by the seismic motion was 39.19 cm, while the relative displacement of the deep sliding surface decreased by 54% compared to 11.62 cm. These results demonstrate that by guiding the artificial shallow sliding body to undergo controllable slip first, the sliding displacement of the deep sliding body can be effectively reduced, thereby improving the overall stability of the slope.

[0026] In summary, by actively guiding the controlled sliding of artificial shallow landslides under seismic loading and utilizing the dynamic coupling effect between landslides, the yield coefficient of deep landslides can be significantly increased, thereby effectively controlling their sliding displacement. This method achieves the seismic resistance objective of "graded energy dissipation and slope stabilization through sliding," enhancing the overall stability of the slope while improving the safety and economy of the engineering project against seismic loads.

[0027] Example 5 A construction method for seismic protection of deep landslides using the slope seismic structure described in any one of claims 1-3, comprising the following steps: S1, top surface finishing of the deep landslide: filling construction is carried out according to the designed slope ratio until the design elevation of the buffer platform is reached, completing the filling and compaction of the top surface of the deep landslide; S2, construction of the artificial soft cushion layer: in the preset area of ​​the top surface of the deep landslide, according to the optimal design parameters determined by formula (13), including the vertical height from the bottom to the top of the artificial sliding surface, the inclination angle of the artificial sliding surface, the cohesion of the artificial sliding surface, and the internal friction angle of the artificial sliding surface, a cushion material with a shear strength less than that of the surrounding soil is uniformly laid to form a continuous artificial soft cushion layer, and a connection surface with the buffer platform is reserved at its front end; S3, construction of the buffer platform: at the front end of the artificial soft cushion layer and at the top of the slope of the deep landslide, according to the designed volume of the artificial shallow landslide and the expected sliding displacement calculated by formula (18) when encountering a major earthquake. Construct a buffer platform and compact and harden or drain the platform area; S4. Construction of the platform retaining dike: A long strip-shaped low dike passive retaining structure is set at the front end of the buffer platform. The material is mainly concrete, masonry or soil-rock mixture. It is used to intercept the soil and loose debris of the upper sliding body and prevent it from spreading downward; S5. Construction of the artificial shallow sliding body: On the artificial soft cushion layer, fill construction is carried out according to the optimal design parameters determined by formula (13), including the vertical height of the bottom of the artificial sliding surface from the top, the inclination angle of the artificial sliding surface, the cohesion of the artificial sliding surface, the internal friction angle of the artificial sliding surface, and the optimal artificial shallow sliding body weight determined by the mass and volume of the artificial shallow sliding body in formula (13), until a complete slope design outline is formed. This part constitutes the artificial shallow sliding body and is physically separated from the deep sliding body by the artificial soft cushion layer; S6. Construction of the slope: The final protection project is carried out on the slope of the deep sliding body and the artificial shallow sliding body.

[0028] The above specific embodiments are used to explain and illustrate the present invention, but not to limit the present invention. Any modifications and changes made to the present invention within the spirit and scope of the claims shall fall within the protection scope of the present invention.

Claims

1. A slope seismic-resistant structure that enhances the stability of deep sliding masses by artificially setting shallow controllable sliding bodies, characterized in that, The slope protection system comprises the following components: a deep sliding mass, which is the existing slope body requiring seismic reinforcement, containing a potential deep sliding surface. This potential deep sliding surface means that when the unreinforced slope body experiences an earthquake alone, the shear stress at its depth exceeds the shear strength of the slope body, forming a continuous sliding surface that causes permanent deformation and overall shear failure along this surface. An artificial weak cushion layer, artificially laid on top of the deep sliding mass, is composed of a material with lower friction and sliding capacity than the surrounding soil and is planar in shape. This artificial weak cushion layer is used to form a defined... An artificial sliding surface with shear strength lower than that of the surrounding slope soil; a buffer platform, which is set together with the artificial weak cushion layer on the top surface of the deep sliding body and located at the front end of the artificial weak cushion layer, is used to receive the soil deposited after the artificial shallow sliding body slides behind it, wherein the front end and the rear end are distinguished along the direction of soil sliding; the width of the buffer platform is determined according to the amount of soil sliding and the sliding displacement of the artificial shallow sliding body; a platform retaining dike is set at the front end of the buffer platform to intercept the soil sliding down from the rear end; the artificial shallow sliding body is the fill slope formed by continuing to fill on the artificial weak cushion layer, which is physically separated from the deep sliding body by the artificial weak cushion layer.

2. The slope seismic-resistant structure according to claim 1, characterized in that, When setting up the artificial sliding surface, the yield coefficient and sliding displacement of the potential deep sliding surface and the artificial sliding surface are calculated by inputting construction parameters. The construction parameters are: the vertical height from the bottom to the top of the artificial sliding surface, the inclination angle of the artificial sliding surface, the cohesion of the artificial sliding surface, the internal friction angle of the artificial sliding surface, and the weight of the artificial shallow sliding surface. By adjusting the construction parameters, the yield coefficient of the artificial sliding surface is made smaller than that of the potential deep sliding surface, ensuring that both the artificial shallow sliding surface and the deep sliding surface remain stable under normal working conditions and small earthquakes. The small earthquake refers to an earthquake that is insufficient to trigger shear deformation of the artificial shallow sliding surface along the artificial sliding surface. The calculation method of yield coefficient and sliding displacement includes the following steps: using subscripts "1" and "2" to distinguish between the artificial shallow sliding surface and the deep sliding surface, where subscript "1" represents the relevant parameters of the artificial shallow sliding surface and subscript "2" represents the relevant parameters of the deep sliding surface; α is the angle between the sliding surface and the horizontal plane. When the subscript of α is 1, the sliding surface is an artificial sliding surface; when the subscript of α is 2, the sliding surface is a potential deep sliding surface; k h ρ is the horizontal seismic motion coefficient, N is the normal force at the bottom of the slider, T is the tangential anti-slip force at the bottom of the slider, m is the mass of the sliding body, W is the weight of the sliding body, γ is the weight of the sliding body, V is the volume of the sliding body, a is the sliding acceleration of the slider, s is the sliding displacement of the slider, g is the gravitational acceleration, and the direction of the seismic motion is horizontal. First, a force analysis is performed on the artificial shallow sliding body, and the analysis process is as follows: Horizontal force equilibrium equation: Vertical force equilibrium equation: By combining (1) and (2), we can obtain the expressions for the bottom normal force N1 and the tangential anti-slip force T1 of the artificial shallow sliding body; Sliding force T1 of artificial shallow sliding body s The anti-slip force T1 exerted by the artificial shallow sliding body is equal in magnitude and opposite in direction, and its expression is as follows: Using the Mohr-Coulomb criterion, the sliding force T1 of the artificial shallow sliding body is... s Ultimate anti-skid force T1 of artificial shallow sliding body f Subtracting them, we get equation (6): Where c1 is the cohesion of the artificial shallow landslide soil and rock mass, φ1 is the internal friction angle of the artificial shallow landslide soil and rock mass, and l1 is the length of the artificial shallow sliding surface; then, the force analysis of the deep landslide is performed, and the analysis process is as follows; the force balance equation in the horizontal direction is: Vertical force equilibrium equation: By combining (7) and (8), we can obtain the expressions for the bottom normal force N2 and the tangential anti-slip force T2 of the deep sliding body; The sliding force T2 of the deep sliding body s The anti-slip force T2 exerted by the deep sliding body is equal in magnitude and opposite in direction, and its expression is as follows: Using the Mohr-Coulomb criterion, the sliding force T2 of the deep sliding body is... s With the ultimate anti-skid force T2 of deep sliding body f Subtracting them, we get equation (12): Where c2 is the cohesion of the deep sliding body rock and soil, φ2 is the internal friction angle of the deep sliding body rock and soil, and l2 is the length of the deep sliding surface; when the sliding force T1 of the artificial shallow sliding body... s Less than the ultimate anti-skid force T1 of the artificial shallow sliding body f When the artificial shallow sliding body is in a stable state, a1=a2=0. Combining equation (6), we can obtain the conditions for the artificial shallow sliding body to slide under seismic load, that is: when the seismic action does not reach the critical threshold for shear slip of the artificial sliding surface, the artificial shallow sliding body will remain in a stable state. Where: k y1 The yield coefficient of the artificial shallow sliding body is m1 = γ1V1 / g; when the sliding force T2 of the deep sliding body is... s Less than the ultimate anti-slip force T2 of the deep sliding body f When the deep sliding body is in a stable state, a1=a2=0. Combining equation (12), we can obtain the condition for the deep sliding body to slide under seismic load, that is: when the seismic action does not reach the critical threshold for the potential deep sliding surface to undergo shear slip, the deep sliding body will remain in a stable state. Where: k y2 ρ is the yield coefficient of the deep sliding body, m2=γ2V2 / g.

3. The slope seismic-resistant structure according to claim 2, characterized in that, During a major earthquake, the artificial shallow slip surface is designed to slide first, ensuring that the displacement of the deep slip body after the artificial slip surface is installed is reduced by 50% or more compared to the displacement of the deep slip body before the artificial slip surface is installed, thereby protecting the deep slip body. The major earthquake refers to an earthquake sufficient to trigger overall deformation of the slope along the potential deep slip surface. In the case where the artificial shallow slip body slides but the deep slip body does not, the sliding force T2 of the deep slip body is... s Less than the ultimate anti-slip force T2 of the deep sliding body f When the sliding acceleration a2 of the deep sliding body is 0, the anti-slip force of the artificial shallow sliding body is fully utilized, T1 s =T1 f Combining equations (6) and (12), we can obtain the critical threshold for shear slippage of deep sliding bodies under seismic load when artificial shallow sliding bodies slide. Equation (15) shows that under large earthquakes, when artificial shallow sliding bodies exist and slide, the conditions for deep sliding bodies to slide are improved compared to when no artificial shallow sliding bodies are present, i.e., k y21 >k y2 ; Where: k y21 Let A1 be the yield coefficient of the deep sliding body under the condition of artificial shallow sliding body sliding; A2 = sinα1tanφ1 + cosα1, A2 = sinα2tanφ2 + cosα2, B2 = cosα2tanφ2 - sinα2; Furthermore, in a large earthquake, when both the artificial shallow and deep sliding bodies slide, the ultimate resistance of the artificial sliding surface and the deep potential sliding surface is fully utilized, T1 s =T1 f T2 s =T2 f Combining equations (6) and (12), we can obtain the sliding acceleration of different sliding bodies; the expression for the sliding acceleration a1 of an artificial shallow sliding body is: The expression for the sliding acceleration a2 of a deep sliding body: By performing double numerical integration on the accelerations (16) and (17) of the slider throughout the entire earthquake motion, the sliding displacements of different sliding bodies along the sliding surface during the entire earthquake phase can be calculated: Where: t is the duration of the ground motion; by adjusting the construction parameters, it is ensured that under the condition of a major earthquake, the calculated displacement of the deep sliding body is reduced by 50% or more compared with the displacement before setting the artificial sliding body, and the seismic stability requirements are met.

4. A construction method for seismic protection of deep landslides using the slope seismic-resistant structure described in claim 3, characterized in that, Includes the following steps: S1. Top surface finishing of deep sliding body: Filling construction is carried out according to the designed slope until the design elevation of the buffer platform is reached, completing the filling and compaction of the top surface of the deep sliding body; S2. Construction of the artificial soft cushion layer: In the preset area of ​​the top surface of the deep sliding body, according to the optimal design parameters determined by formula (13), including the vertical height from the bottom to the top of the artificial sliding surface, the inclination angle of the artificial sliding surface, the cohesion of the artificial sliding surface, and the internal friction angle of the artificial sliding surface, a cushion material with a shear strength less than that of the surrounding soil is evenly laid to form a continuous artificial soft cushion layer, and a connection surface with the buffer platform is reserved at its front end; S3. Construction of the buffer platform: At the front end of the artificial soft cushion layer and the top of the slope of the deep sliding body, a buffer platform is constructed according to the designed volume of the artificial shallow sliding body and the expected sliding displacement calculated by formula (18) when encountering a major earthquake, and the platform area is compacted and surface hardened or drained. S4. Construction of the platform retaining dike: A long strip-shaped low dike-like passive retaining structure is set at the front end of the buffer platform. The material is mainly concrete, masonry or a mixture of soil and rock. It is used to intercept the soil and loose debris of the upper sliding body and prevent it from spreading downwards. S5. Construction of the artificial shallow sliding body: On the artificial soft cushion layer, according to the optimal design parameters determined by formula (13), including the vertical height from the bottom to the top of the artificial sliding surface, the inclination angle of the artificial sliding surface, the cohesion of the artificial sliding surface, the internal friction angle of the artificial sliding surface, and the optimal artificial shallow sliding body weight determined by the mass and volume of the artificial shallow sliding body in formula (13), the filling construction is carried out until a complete slope design outline is formed. This part constitutes the artificial shallow sliding body and is physically separated from the deep sliding body by the artificial soft cushion layer. S6. Construction of the slope: The final protection project is carried out on the slope surface of the deep sliding body and the artificial shallow sliding body.

5. The application of the slope seismic-resistant structure according to any one of claims 1-3 or the construction method according to claim 4 in slope seismic resistance.

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