半空间饱和土中孔洞对波场散射问题的边界元法分析  

INFLUCENCE OF CAVITY ON SCATTERING OF WAVE FIELD IN HALF SPACE SATURATED SOIL USING BOUNDARY ELEMENT METHOD

作　　者：张鸿[1,2] 高谦[1] 徐斌[2] 徐满清[2] 

机构地区：[1]北京科技大学土木与环境工程学院,北京100083 [2]南昌工程学院土木与建筑工程学院,江西南昌330099

出　　处：《工程力学》2013年第12期228-235,254,共9页Engineering Mechanics

基　　金：国家自然科学基金项目(50969007;51269021);江西省自然科学基金项目(20114BAB206012;20133ACB20006);江西省教育厅科技项目(GJJ12629;GJJ13754)

摘　　要：根据饱和土Biot理论及孔洞边界特性,通过引入势函数,利用Betti互易定理,建立了半无限饱和土体中孔洞对波场散射问题的边界元积分方程,讨论了边界积分方程的奇异性,并分析了饱和土体特性及入射波场等对孔洞应力集中与孔压集中系数的影响效果。通过与已知文献结果比较,验证该文算法的正确性。数值结果表明:饱和土体中流、固耦合程度、压缩性、透水性等对波场散射有较大的影响:随饱和土体中流、固二相耦合程度增大,孔洞应力集中系数增大,孔洞的散射作用增强;随饱和土体压缩性减小,孔洞应力集中系数增大;而随饱和土体透水性降低,孔洞应力集中系数、孔压集中系数都增大。This paper establishes the boundary element integral equation describing the influence of cavity on wave-field scattering in semi-unlimited saturated soil, based on Biot＇s theory of saturated soil and boundary features of cavity. By introducing the potential function and Betti＇s reciprocal theory, the singularity of the boundary integral equation was discussed. The effect of saturated soil features and incidence wave field on dynamic stress concentration and pore pressure concentration coefficient was analyzed. The correctness of the algorithm was validated by comparing the values acquired in this study with known literature results. The numerical result indicates that the coupling degree between fluid and solid in saturated soil as well as compression and permeability have great influences on wave-field scattering. As the coupling degrees of the fluid and solid phases in saturated soil increase, the dynamic stress concentration coefficient increases and the cavity scattering effect is strengthened. As the compression of saturated soil decreases, the dynamic stress concentration coefficient increases. As the permeability of saturated soil decreases, the dynamic stress concentration coefficient and pore pressure increase.

关 键 词：饱和土 孔洞 边界积分方程 散射 动应力集中系数 GREEN函数 

分 类 号：TU471[建筑科学—结构工程]