基于强度折减法的格仓式圆筒围堰稳定性有限元分析
|
摘要
格仓式圆筒作为深厚软土地基上人工岛围堰主体结构,其在围堰内部填土、外部尚未抛石斜坡堤工况下作用荷载复杂,难以采用有限元加载系数法进行稳定性分析。结合工程算例,基于强度折减法建立格仓式圆筒围堰三维弹塑性有限元分析模型。建议了基于强度折减系数-位移(Fv-S)曲线突变点法失稳判别标准,得到格仓式圆筒失稳模式和稳定性安全系数。结果表明格仓式圆筒结构失稳模式为筒体倾覆破坏,稳定性安全系数随格体入土深度增加而增大,随水平荷载和后方堆载的增加而减小。研究成果可为格仓式圆筒围堰工程设计提供借鉴和参考。
Cellular bucket is used as the bearing structure of artificial island in soft soil subgrades. The service conditions are complicated when the cofferdam is backfilled inside and the rubble mound breakwater has not formed outside. It is difficult to use finite element loading coefficient method to analyze stability. Combined with an engineering example, we established a3-dimensional elastic-plastic finite element analysis model based on strength reduction method, proposed the criteria that determine the instability of the cellular bucket, namely the catastrophe point criterion based on the strength reduction factor-displacement curves(Fv-S), and obtained the instability modes and stability factors of the cellular bucket. Results show that instability modes of the cellular bucket are overturning failure of the bucket. Safety factors increase with the increase of penetrating depth, and decrease with the increase of horizontal loads and uniform distribution loads inside the cofferdam. The results could be served as a useful reference for the engineering design of the cellular bucket structures.
Cellular bucket is used as the bearing structure of artificial island in soft soil subgrades. The service conditions are complicated when the cofferdam is backfilled inside and the rubble mound breakwater has not formed outside. It is difficult to use finite element loading coefficient method to analyze stability. Combined with an engineering example, we established a3-dimensional elastic-plastic finite element analysis model based on strength reduction method, proposed the criteria that determine the instability of the cellular bucket, namely the catastrophe point criterion based on the strength reduction factor-displacement curves(Fv-S), and obtained the instability modes and stability factors of the cellular bucket. Results show that instability modes of the cellular bucket are overturning failure of the bucket. Safety factors increase with the increase of penetrating depth, and decrease with the increase of horizontal loads and uniform distribution loads inside the cofferdam. The results could be served as a useful reference for the engineering design of the cellular bucket structures.
引文
[1]王刚,陈杨,张建民.大圆筒结构倾覆稳定分析的有限元法[J].岩土力学,2006,27(2):238-241.WANG Gang,CHEN Yang,ZHANG Jian-min,Finite element method for analyzing overturn stability of large cylindrical structures[J].Rock and Soil Mechanics,2006,27(2):238-241.
[2]范庆来,栾茂田,杨庆.软基上沉入式大圆筒结构的水平承载力分析[J].岩土力学,2004,25(S2):191-195.FAN Qing-lai,LUAN Mao-tian,YANG Qing.Numerical analysis of lateral load bearing capacity of large cylindrical structures on soft foundations[J].Rock and Soil Mechanics,2004,25(S2):191-195.
[3]范庆来,栾茂田,杨庆,等.考虑循环软化效应的软基上深埋大圆筒结构承载力分析[J].大连理工大学学报,2006,46(5):702-706.FAN Qing-lai,LUAN Mao-tian,YANG Qing,et al.Analyses of bearing capacity for deeply-buried large-diameter cylindrical structure on soft clay considering cyclic-softening effect[J].Journal of Dalian University of Technology,2006,46(5):702-706.
[4]范庆来,栾茂田,倪宏革.循环荷载作用下软基上大圆筒结构弹塑性有效应力分析[J].水利学报,2008,39(7):836-842.FAN Qing-lai,LUAN Mao-tian,NI Hong-ge.Elasto-plastic effective stress analysis on soft soil foundation of large-diameter cylindrical structure subjected to cyclic loading[J].Journal of Hydraulic Engineering,2008,39(7):836-842.
[5]肖忠,王元战,及春宁.筒型基础防波堤稳定性有限元数值分析[J].土木工程学报,2009,42(7):119-125.XIAO Zhong,WANG Yuan-zhan,JI Chun-ning.Finite element analysis for the stability of the bucket foundation breakwater[J].China Civil Engineering Journal,2009,42(7):119-125.
[6]肖忠,王元战,及春宁,等.波浪作用下加固软基上大圆筒结构稳定性分析[J].岩土力学,2010,31(8):2 648-2 654.XIAO Zhong,WANG Yuan-zhan,JI Chun-ning,et al.Stability analysis of large cylindrical structure for strengthening soft foundation under wave loads[J].Rock and Soil Machanics,2010,31(8):2 648-2 654.
[7]王元战,焉振,王禹迟.格型钢板桩结构有限元数值分析[J].岩土力学,2013,34(4):1 163-1 170.WANG Yuan-zhan,YAN Zhen,WANG Yu-chi.Finite elemental numerical analysis of cellular steel sheet pile structure[J].Rock and Soil Mechanics,2013,34(4):1 163-1 170.
[8]陈力华,靳晓光.有限元强度折减法中边坡三种失效判据的适用性研究[J].土木工程学报,2012,45(9):136-146.CHEN Li-hua,JIN Xiao-guang.Study on the applicability of three criteria for slope instability using finite element strength reduction method[J].China Civil Engineering Journal,2012,45(9):136-146.
[9]年廷凯,栾茂田,杨庆,等.基于强度折减弹塑性有限元法的抗滑桩加固边坡稳定性分析[J].岩土力学,2007,28(S):558-562.NIAN Ting-kai,LUAN Mao-tian,YANG Qing,et al.Stability analysis of slope reinforced with piles by using strength reduction FEM[J].Rock and Soil Mechanics,2007,28(S):558-562.
[2]范庆来,栾茂田,杨庆.软基上沉入式大圆筒结构的水平承载力分析[J].岩土力学,2004,25(S2):191-195.FAN Qing-lai,LUAN Mao-tian,YANG Qing.Numerical analysis of lateral load bearing capacity of large cylindrical structures on soft foundations[J].Rock and Soil Mechanics,2004,25(S2):191-195.
[3]范庆来,栾茂田,杨庆,等.考虑循环软化效应的软基上深埋大圆筒结构承载力分析[J].大连理工大学学报,2006,46(5):702-706.FAN Qing-lai,LUAN Mao-tian,YANG Qing,et al.Analyses of bearing capacity for deeply-buried large-diameter cylindrical structure on soft clay considering cyclic-softening effect[J].Journal of Dalian University of Technology,2006,46(5):702-706.
[4]范庆来,栾茂田,倪宏革.循环荷载作用下软基上大圆筒结构弹塑性有效应力分析[J].水利学报,2008,39(7):836-842.FAN Qing-lai,LUAN Mao-tian,NI Hong-ge.Elasto-plastic effective stress analysis on soft soil foundation of large-diameter cylindrical structure subjected to cyclic loading[J].Journal of Hydraulic Engineering,2008,39(7):836-842.
[5]肖忠,王元战,及春宁.筒型基础防波堤稳定性有限元数值分析[J].土木工程学报,2009,42(7):119-125.XIAO Zhong,WANG Yuan-zhan,JI Chun-ning.Finite element analysis for the stability of the bucket foundation breakwater[J].China Civil Engineering Journal,2009,42(7):119-125.
[6]肖忠,王元战,及春宁,等.波浪作用下加固软基上大圆筒结构稳定性分析[J].岩土力学,2010,31(8):2 648-2 654.XIAO Zhong,WANG Yuan-zhan,JI Chun-ning,et al.Stability analysis of large cylindrical structure for strengthening soft foundation under wave loads[J].Rock and Soil Machanics,2010,31(8):2 648-2 654.
[7]王元战,焉振,王禹迟.格型钢板桩结构有限元数值分析[J].岩土力学,2013,34(4):1 163-1 170.WANG Yuan-zhan,YAN Zhen,WANG Yu-chi.Finite elemental numerical analysis of cellular steel sheet pile structure[J].Rock and Soil Mechanics,2013,34(4):1 163-1 170.
[8]陈力华,靳晓光.有限元强度折减法中边坡三种失效判据的适用性研究[J].土木工程学报,2012,45(9):136-146.CHEN Li-hua,JIN Xiao-guang.Study on the applicability of three criteria for slope instability using finite element strength reduction method[J].China Civil Engineering Journal,2012,45(9):136-146.
[9]年廷凯,栾茂田,杨庆,等.基于强度折减弹塑性有限元法的抗滑桩加固边坡稳定性分析[J].岩土力学,2007,28(S):558-562.NIAN Ting-kai,LUAN Mao-tian,YANG Qing,et al.Stability analysis of slope reinforced with piles by using strength reduction FEM[J].Rock and Soil Mechanics,2007,28(S):558-562.