As a combined supporting structure,the anchor cable and lattice beam have a complex interaction with the slope body.In order to investigate the seismic behaviors of the slope reinforced by anchor cable and lattice bea...As a combined supporting structure,the anchor cable and lattice beam have a complex interaction with the slope body.In order to investigate the seismic behaviors of the slope reinforced by anchor cable and lattice beam,a largescale shaking table test was carried out on a slope model(geometric scale of 1:20)by applying recorded and artificial seismic waves with different amplitudes.The acceleration and displacement of the slope,the displacement of lattice beam and the axial force of anchor cable were obtained to study the interaction between the slope and the supporting structure.The test results show that:(1)the acceleration responses of the slope at different relative elevations display obvious nonlinear characteristics with increasing of the peak ground acceleration(PGA)of the inputted seismic waves,and the weak intercalated layer has a stronger effect on acceleration amplification at the upper part of the slope than that at the lower part of the slope;(2)the frequency component near the second dominant frequency is significantly magnified by the interaction between the slope and the supporting structure;(3)the anchor cables at the upper part of the slope have larger peak and residual axial forces than that at the lower part of the slope,and the prestress loss of the anchor cable first occurs at the top of the slope and then passes down;(4)the peak and residual displacements inside the slope and on the lattice beam increase with the increase of relative elevation.When the inputted PGA is not greater than 0.5 g,the combined effect of anchor cable and lattice beam is remarkable for stabilizing the middle and lower parts of the potential sliding body.The research results can provide a reference for the seismic design of such slope and the optimization of supporting structure.展开更多
With the rapid development of water facilities, hydroelectric projects, highways and railways in China, beam-anchor reinforcement has been widely used to stabiliZe slopes in recent years. But the theory for the design...With the rapid development of water facilities, hydroelectric projects, highways and railways in China, beam-anchor reinforcement has been widely used to stabiliZe slopes in recent years. But the theory for the design of beam-anchor reinforcement is far behind the application. Cross beam-ground anchor reinforcement is a combination of beams and anchors forming a new structure to prevent slope sliding. The forces in the beams are discussed using theoretical analysis and numerical modeling. The Winkler model is used to analyze the beams, and reasonable values of λ, length, spacing and cantilevered length for the beams are determined through a theoretical analysis. A three-dimensional finite element method is adopted to model the interaction of the beams and soils and a structure analysis is applied to treat the beams and to study the stress distribution in external and internal beams. The analytical results show that it is better to satisfy λ≥2π, the spacing between anchors ls should be lsλ〈π/2 and cantilever length should be （0.3-0.5）ls for the optimum design. The numerical results show that the same design can be used for all beams in different directions, including the internal and external beams. The application of the analytical method for reinforcement beam analysis is acceptable. It is better to choose a safety coefficient of 1.3 for design based on the analytical method for safety.展开更多
During the construction of some large-scale rock engineering,high-steep slopes and insufficient slope stability induced by unloading fissures are often encountered.For the reinforcement of these slopes,some techniques...During the construction of some large-scale rock engineering,high-steep slopes and insufficient slope stability induced by unloading fissures are often encountered.For the reinforcement of these slopes,some techniques(including conventional pre-stressed anchoring cable and unconventional anchoring hole)are usually utilized,however,having several obvious defects.Thus,it is very difficult for a designer to design an efficient reinforcement scheme for the high-steep slopes.For this reason,the authors develop the pre-stressed anchoring beam technique,in which tensile capacity of pre-stressed structures are fully utilized.It is analyzed that the new technique is characterized by multi-functions,including engineering investigation,efficient reinforcement,drainage,monitoring and urgent strength supplement,and hoped to be extensively applicable in the reinforcement of high-steep slopes.展开更多
基金National Key R&D Program of China(Grant No.2017YFC0504901)the Science and Technology Plan Projects of Sichuan Province(Grant No 2015SZ0068)
文摘As a combined supporting structure,the anchor cable and lattice beam have a complex interaction with the slope body.In order to investigate the seismic behaviors of the slope reinforced by anchor cable and lattice beam,a largescale shaking table test was carried out on a slope model(geometric scale of 1:20)by applying recorded and artificial seismic waves with different amplitudes.The acceleration and displacement of the slope,the displacement of lattice beam and the axial force of anchor cable were obtained to study the interaction between the slope and the supporting structure.The test results show that:(1)the acceleration responses of the slope at different relative elevations display obvious nonlinear characteristics with increasing of the peak ground acceleration(PGA)of the inputted seismic waves,and the weak intercalated layer has a stronger effect on acceleration amplification at the upper part of the slope than that at the lower part of the slope;(2)the frequency component near the second dominant frequency is significantly magnified by the interaction between the slope and the supporting structure;(3)the anchor cables at the upper part of the slope have larger peak and residual axial forces than that at the lower part of the slope,and the prestress loss of the anchor cable first occurs at the top of the slope and then passes down;(4)the peak and residual displacements inside the slope and on the lattice beam increase with the increase of relative elevation.When the inputted PGA is not greater than 0.5 g,the combined effect of anchor cable and lattice beam is remarkable for stabilizing the middle and lower parts of the potential sliding body.The research results can provide a reference for the seismic design of such slope and the optimization of supporting structure.
文摘With the rapid development of water facilities, hydroelectric projects, highways and railways in China, beam-anchor reinforcement has been widely used to stabiliZe slopes in recent years. But the theory for the design of beam-anchor reinforcement is far behind the application. Cross beam-ground anchor reinforcement is a combination of beams and anchors forming a new structure to prevent slope sliding. The forces in the beams are discussed using theoretical analysis and numerical modeling. The Winkler model is used to analyze the beams, and reasonable values of λ, length, spacing and cantilevered length for the beams are determined through a theoretical analysis. A three-dimensional finite element method is adopted to model the interaction of the beams and soils and a structure analysis is applied to treat the beams and to study the stress distribution in external and internal beams. The analytical results show that it is better to satisfy λ≥2π, the spacing between anchors ls should be lsλ〈π/2 and cantilever length should be （0.3-0.5）ls for the optimum design. The numerical results show that the same design can be used for all beams in different directions, including the internal and external beams. The application of the analytical method for reinforcement beam analysis is acceptable. It is better to choose a safety coefficient of 1.3 for design based on the analytical method for safety.
基金This paper was financially supported by the Project 973 of Chinese National Program of Basic Research （No. 2002CB412701） the National Natural Science Foundation （No. 40502027）the Project of Innovation Program of Chinese Academy of Sciences （No. KZCX2-306）.
文摘During the construction of some large-scale rock engineering,high-steep slopes and insufficient slope stability induced by unloading fissures are often encountered.For the reinforcement of these slopes,some techniques(including conventional pre-stressed anchoring cable and unconventional anchoring hole)are usually utilized,however,having several obvious defects.Thus,it is very difficult for a designer to design an efficient reinforcement scheme for the high-steep slopes.For this reason,the authors develop the pre-stressed anchoring beam technique,in which tensile capacity of pre-stressed structures are fully utilized.It is analyzed that the new technique is characterized by multi-functions,including engineering investigation,efficient reinforcement,drainage,monitoring and urgent strength supplement,and hoped to be extensively applicable in the reinforcement of high-steep slopes.
