区域边坡稳定性分析的研究一直是地质灾害研究的重点。物理模型能有效地反映边坡稳定性预测的物理力学机制,且可解释性较强。但现有物理模型未能真实地考虑地形坡度因素对边坡稳定性计算结果的影响,且其大多未考虑边坡土体力学参数的空...区域边坡稳定性分析的研究一直是地质灾害研究的重点。物理模型能有效地反映边坡稳定性预测的物理力学机制,且可解释性较强。但现有物理模型未能真实地考虑地形坡度因素对边坡稳定性计算结果的影响,且其大多未考虑边坡土体力学参数的空间变异性特征。为解决这些问题,对无限边坡模型的地形坡度进行定值优化,利用地形坡度分布特征来修正边坡土体的抗剪强度参数,并利用基于概率论的蒙特卡洛法探讨边坡土体抗剪强度参数的空间变异性,最终开发出全新的边坡可靠度计算模型(Regional Infinite Slope and Probability theory based slope Reliability Mapping,RISPRM)。最后以江西省赣州市宁都县为研究区,分别采用RISPRM模型和代表传统物理模型的SINMAP模型对该区域边坡可靠度进行计算,经频率比和预测率曲线精度对比,结果显示:RISPRM模型相对于传统物理模型能更好地预测危险区域滑坡灾害,预测效果更好且更符合野外实际情况;该模型有效地解决了传统物理模型中存在的低坡度区边坡稳定性计算结果随坡度变化不稳定、中高坡度区边坡稳定性计算结果随坡度增大而单调下降以及计算结果未考虑地质条件的时间和空间变化等问题。展开更多
A series of centrifuge model tests of sandy slopes were conducted to study the dynamic behavior of pile-reinforced slopes subjected to various motions.Time histories of accelerations,bending moments and pile earth pre...A series of centrifuge model tests of sandy slopes were conducted to study the dynamic behavior of pile-reinforced slopes subjected to various motions.Time histories of accelerations,bending moments and pile earth pressures were obtained during excitation of the adjusted El Centro earthquake and a cyclic motion.Under a realistic earthquake,the overall response of the pile-reinforced slope is lower than that of the non-reinforced slope.The histories of bending moments and dynamic earth pressures reach their maximums soon after shaking started and then remain roughly stable until the end of shaking.Maximum moments occur at the height of 3.5 m,which is the deeper section of the pile,indicating the interface between the active loading and passive resistance regions.The dynamic earth pressures above the slope base steadily increase with the increase of height of pile.For the model under cyclic input motion,response amplitudes at different locations in the slope are almost the same,indicating no significant response amplification.Both the bending moment and earth pressure increase gradually over a long period.展开更多
For fully understanding the hydrological dynamics of an infinite terraced slope, the infiltration process was studied by employing the Green and Ampt infiltration model. The limit equilibrium method and the Mohr-Coulo...For fully understanding the hydrological dynamics of an infinite terraced slope, the infiltration process was studied by employing the Green and Ampt infiltration model. The limit equilibrium method and the Mohr-Coulomb failure criterion were adopted to derive a stability model for the infinite terraced slope subjected to an intense rainfall. Numerical simulation was performed for verifying its applicability. The results of numerical simulation indicate that a set of stepped wetting fronts are found during infiltration, and the infiltration of terraced slope covered by coarse-textured soils can be approximated as one-dimensional infiltration. The potential sliding surfaces from the numerical method are all parallel to the slope line, and the proposed model and framework can provide an approximate method of estimating how the infiltration affects the stability of an infinite terraced slope.展开更多
文摘区域边坡稳定性分析的研究一直是地质灾害研究的重点。物理模型能有效地反映边坡稳定性预测的物理力学机制,且可解释性较强。但现有物理模型未能真实地考虑地形坡度因素对边坡稳定性计算结果的影响,且其大多未考虑边坡土体力学参数的空间变异性特征。为解决这些问题,对无限边坡模型的地形坡度进行定值优化,利用地形坡度分布特征来修正边坡土体的抗剪强度参数,并利用基于概率论的蒙特卡洛法探讨边坡土体抗剪强度参数的空间变异性,最终开发出全新的边坡可靠度计算模型(Regional Infinite Slope and Probability theory based slope Reliability Mapping,RISPRM)。最后以江西省赣州市宁都县为研究区,分别采用RISPRM模型和代表传统物理模型的SINMAP模型对该区域边坡可靠度进行计算,经频率比和预测率曲线精度对比,结果显示:RISPRM模型相对于传统物理模型能更好地预测危险区域滑坡灾害,预测效果更好且更符合野外实际情况;该模型有效地解决了传统物理模型中存在的低坡度区边坡稳定性计算结果随坡度变化不稳定、中高坡度区边坡稳定性计算结果随坡度增大而单调下降以及计算结果未考虑地质条件的时间和空间变化等问题。
基金Project(50639060) supported by the National Natural Science Foundation of ChinaProject(610103002) supported by the State Key Laboratory of Hydroscience and Engineering,Tsinghua University,China
文摘A series of centrifuge model tests of sandy slopes were conducted to study the dynamic behavior of pile-reinforced slopes subjected to various motions.Time histories of accelerations,bending moments and pile earth pressures were obtained during excitation of the adjusted El Centro earthquake and a cyclic motion.Under a realistic earthquake,the overall response of the pile-reinforced slope is lower than that of the non-reinforced slope.The histories of bending moments and dynamic earth pressures reach their maximums soon after shaking started and then remain roughly stable until the end of shaking.Maximum moments occur at the height of 3.5 m,which is the deeper section of the pile,indicating the interface between the active loading and passive resistance regions.The dynamic earth pressures above the slope base steadily increase with the increase of height of pile.For the model under cyclic input motion,response amplitudes at different locations in the slope are almost the same,indicating no significant response amplification.Both the bending moment and earth pressure increase gradually over a long period.
基金Project(51178423)supported by the National Natural Science Foundation of China
文摘For fully understanding the hydrological dynamics of an infinite terraced slope, the infiltration process was studied by employing the Green and Ampt infiltration model. The limit equilibrium method and the Mohr-Coulomb failure criterion were adopted to derive a stability model for the infinite terraced slope subjected to an intense rainfall. Numerical simulation was performed for verifying its applicability. The results of numerical simulation indicate that a set of stepped wetting fronts are found during infiltration, and the infiltration of terraced slope covered by coarse-textured soils can be approximated as one-dimensional infiltration. The potential sliding surfaces from the numerical method are all parallel to the slope line, and the proposed model and framework can provide an approximate method of estimating how the infiltration affects the stability of an infinite terraced slope.
