饱和弱化与液化土层的水平极限抗力  

Ultimate lateral resistances of saturated degraded and liquefied strata

作　　者：王建华[1] 周扬锐[2] 

机构地区：[1]天津大学岩土工程研究所,天津300072 [2]中海油田服务股份有限公司工程勘察中心,天津300451

出　　处：《世界地震工程》2010年第4期37-42,共6页World Earthquake Engineering

基　　金：国家自然科学基金项目(50579050)

摘　　要：通过给饱和砂土层施加反压,模拟地震荷载作用下具有残余孔压的饱和弱化、液化土层。选择粉质细砂与细砂,进行了18组水平荷载作用下桩与饱和弱化、液化土层相互作用的模型试验,研究了饱和弱化、液化土层水平极限抗力随土层残余孔压增加的变化规律。结果表明,随土层中残余孔压增加,水平极限抗力逐渐降低,土层液化后的水平极限抗力大约降低80%~90%。通过定义饱和弱化、液化土层的强度,定量分析了饱和弱化、液化砂土的强度参数与水平极限抗力之间关系。又通过引入土层的残余孔压比折减系数,建立了确定饱和弱化、液化土层等效强度的关系式,进而提出了一种按等效强度确定饱和弱化、液化土层水平极限抗力的方法。Saturated degraded and liquefied sand soil layers with the residual pore water pressures are simulated under seismic loads by applying backpressures to saturated sand soil.The silty fine sand and the fine sand were chosen and eighteen model tests of interactions of lateral-loaded piles and the saturated degraded or liquefied sand soil layers were conducted for researching variations of ultimate lateral resistances of soil layers with the increase of residual pore water pressures in the sand soil layers.Test results show that ultimate resistances gradually decrease with the increase of residual pore water pressures by 80% to 90% after sand soil liquefaction.The relationship between the resistance and the strength is quantitatively analyzed by defining the strength of the saturated degraded and liquefied sand soil layers.The relationship to determine the equivalent strength of the degraded and liquefied sand soil layers is further established by defining the scale factor of residual pore water pressures.The method is finally developed for determining ultimate lateral resistances of the degraded and liquefied sand soil layers based on equivalent strength parameters.

关 键 词：桩水平极限抗力 液化砂中的桩 砂土液化 P-Y曲线 

分 类 号：TU411[建筑科学—岩土工程] P315.98[建筑科学—土工工程]