In order to study the stability control mechanism of a concave slope with circular landslide, and remove the influence of differences in shape on slope stability, the limit analysis method of a simplified Bishop metho...In order to study the stability control mechanism of a concave slope with circular landslide, and remove the influence of differences in shape on slope stability, the limit analysis method of a simplified Bishop method was employed. The sliding body was divided into strips in a three-dimensional model, and the lateral earth pressure was put into mechanical analysis and the three-dimensional stability analysis methods applicable for circular sliding in concave slope were deduced. Based on geometric structure and the geological parameters of a concave slope, the influence rule of curvature radius and the top and bottom arch height on the concave slope stability were analyzed. The results show that the stability coefficient decreases after growth, first in the transition stage of slope shape from flat to concave, and it has been confirmed that there is a best size to make the slope stability factor reach a maximum. By contrast with average slope, the stability of a concave slope features a smaller range of ascension with slope height increase, which indicates that the enhancing effect of a concave slope is apparent only with lower slope heights.展开更多
The sliding forms of weak sloped and horizontal subgrades during the sliding process differ.In addition,the sliding form of weakly sloped subgrades exhibits considerable slippage and asymmetry.The accuracy of traditio...The sliding forms of weak sloped and horizontal subgrades during the sliding process differ.In addition,the sliding form of weakly sloped subgrades exhibits considerable slippage and asymmetry.The accuracy of traditional slice methods for computing the stability safety factor of weakly sloped subgrades is insufficient for a subgrade design.In this study,a novel modified Bishop method was developed to improve the accuracy of the stability safety factor for different inclination angles.The instability mechanism of the weakly sloped subgrade was considered in the proposed method using the“influential force”and“additional force”concepts.The“additional force”reflected the weight effect of the embankment fill,whereas the“influential force”reflected the effect of the potential energy difference.Numerical simulations and experimental tests were conducted to evaluate the advantages of the proposed modified Bishop method.Compared with the traditional slice method,the error between the proposed method and the exact value is less than 32.3%in calculating the safety factor.展开更多
Based on Bishop's model and by applying the first and second order mean deviations method, an approximative solution method for the first and second order partial derivatives of functional function was deduced acc...Based on Bishop's model and by applying the first and second order mean deviations method, an approximative solution method for the first and second order partial derivatives of functional function was deduced according to numerical analysis theory. After complicated multi-independent variables implicit functional function was simplified to be a single independent variable implicit function and rule of calculating derivative for composite function was combined with principle of the mean deviations method, an approximative solution format of implicit functional function was established through Taylor expansion series and iterative solution approach of reliability degree index was given synchronously. An engineering example was analyzed by the method. The result shows its absolute error is only 0.78% as compared with accurate solution.展开更多
基金financially supported by the China Postdoctoral Science Foundation(No.2015M580491)the National Natural Science Foundation of China(No.51404262)+1 种基金the Natural Science Foundation of Jiangsu Province(No.BK20140213)the National High Technology Research and Development Program of China(No.2012AA062004)
文摘In order to study the stability control mechanism of a concave slope with circular landslide, and remove the influence of differences in shape on slope stability, the limit analysis method of a simplified Bishop method was employed. The sliding body was divided into strips in a three-dimensional model, and the lateral earth pressure was put into mechanical analysis and the three-dimensional stability analysis methods applicable for circular sliding in concave slope were deduced. Based on geometric structure and the geological parameters of a concave slope, the influence rule of curvature radius and the top and bottom arch height on the concave slope stability were analyzed. The results show that the stability coefficient decreases after growth, first in the transition stage of slope shape from flat to concave, and it has been confirmed that there is a best size to make the slope stability factor reach a maximum. By contrast with average slope, the stability of a concave slope features a smaller range of ascension with slope height increase, which indicates that the enhancing effect of a concave slope is apparent only with lower slope heights.
基金This study was sponsored by the National Natural Science Foundation of China(Grant No.51609071)the Fundamental Research Funds for the Central Universities(Nos.B200202087,B200204032).
文摘The sliding forms of weak sloped and horizontal subgrades during the sliding process differ.In addition,the sliding form of weakly sloped subgrades exhibits considerable slippage and asymmetry.The accuracy of traditional slice methods for computing the stability safety factor of weakly sloped subgrades is insufficient for a subgrade design.In this study,a novel modified Bishop method was developed to improve the accuracy of the stability safety factor for different inclination angles.The instability mechanism of the weakly sloped subgrade was considered in the proposed method using the“influential force”and“additional force”concepts.The“additional force”reflected the weight effect of the embankment fill,whereas the“influential force”reflected the effect of the potential energy difference.Numerical simulations and experimental tests were conducted to evaluate the advantages of the proposed modified Bishop method.Compared with the traditional slice method,the error between the proposed method and the exact value is less than 32.3%in calculating the safety factor.
基金Project(50378036) supported by the National Natural Science Foundation of ChinaProject(200503) supported by Foundation of Communications Department of Hunan Province, China
文摘Based on Bishop's model and by applying the first and second order mean deviations method, an approximative solution method for the first and second order partial derivatives of functional function was deduced according to numerical analysis theory. After complicated multi-independent variables implicit functional function was simplified to be a single independent variable implicit function and rule of calculating derivative for composite function was combined with principle of the mean deviations method, an approximative solution format of implicit functional function was established through Taylor expansion series and iterative solution approach of reliability degree index was given synchronously. An engineering example was analyzed by the method. The result shows its absolute error is only 0.78% as compared with accurate solution.
