纵向剪切地震波作用下非线性地基基床系数对地下区间隧道动力响应的影响  

Effect of nonlinear foundation bedding coefficient on dynamic response of underground tunnel structures under longitudinal seismic wave

作　　者：徐英乾[1] 戚承志[1] 沙曼[1] 

机构地区：[1]北京建筑工程学院,北京市高校工程结构与新材料工程研究中心,北京100044

出　　处：《世界地震工程》2013年第3期113-120,共8页World Earthquake Engineering

基　　金：北京市自然基金资助项目(KZ200810016007);北京市属高等学校创新团队建设与教师职业发展计划项目;国家自然基金资助项目(51174012);国家重点基础研究发展计划(973)项目(2010CB732003)

摘　　要：利用Winkler弹性地基梁模拟地下区间隧道,正弦波模拟纵向剪切地震波,导出了弹性地基梁的振动方程。选取广东地区典型的粉质粘土,利用现有的实验数据,以双曲型函数拟合了土的压力-沉降位移曲线(p-s曲线),在此基础上利用面积相等原则求出土体等效线性地基基床系数和割线型的地基基床系数,并代入到弹性地基梁的振动方程,最终通过Matlab软件直接对此非线性方程求解,比较了在相同设防加速度下土体等效线性、割线型地基基床系数以及初始线性地基基床系数对应的地下区间隧道的动力响应。并提出了一种地基基床系数折减的简单方法,此方法能把非线性的问题转化成线性问题,因而减少了计算量。案例分析表明,所提简化分析方法是可行的,可以为工程实践提供参考。In the case that Winkler-type elastic foundation beam model was used to model the dynamic behavior of underground running tunnel and sine-type wave was used to simulate the longitudinal seismic wave, Vibration equa- tion of elastic foundament beam was deduced. Selecting the typical silty clay in Guang Dong Province, and using the available experimental data, we fitted the of pressure -settlement curves of soil by hyperbolic type function（p - s curve）, and then equivalent linear and secant-type foundation bedding coefficients of the soil was obtained based on the principle of equal area of p - s curve. Substituting the equivalent foundation bedding coefficient into the mo- tion equation of the Winkler-type elastic foundation beam, we solved the nonlinear differential equation by using Matlab software and compared the difference of dynamic response of umderground tunnel structure as using equiva- lent linear bedding coefficient, secant-type bedding coefficient and initial linear foundation bedding coefficient un- der same seismic fortification acceleration. At last a simplified method for reduction of foundation bedding coeffi- cient was put forward to transform the nonlinear problem into linear one and to reduce the calculation. The case an- alyses show that the presented simplified method is feasible and can give a reference to engineering practice.

关 键 词：区间隧道 动力响应 P-S曲线 地基基床系数 

分 类 号：TU443[建筑科学—岩土工程]