多排柱腔构成的非连续屏障对SV波的隔离

运用复变函数的保角映射方法和波函数展开法，根据柱腔壁处土体完全自由，即应力为零的边界条件，得到了多排柱腔构成的屏障对入射平面SV波的多重散射的理论解，根据屏障后归一化位移(入射和散射SV波产生的总位移与入射SV波在同一点产生的位移之比)的变化规律，着重分析了多排(双排和三排)和单排柱腔对平面SV波的隔离效果，结果表明：(1) 双排和三排柱腔屏障的隔离效果明显好于单排柱腔屏障；(2) 当入射SV波的频率较低时，双排并列正对的柱腔屏障的隔离效果较好，而当频率较高时，双排交错的柱腔屏障的隔离效果较好；(3) 三排梅花桩布置的柱腔屏障的隔离效果好于双排柱腔，当入射SV波的频率较高时，屏障后有近3/4的面积的隔离效果都超过了60%；(4) 无论是单排还是多排柱腔屏障，当入射SV波频率较高时，靠近屏障边缘区域的隔离效果要好于中心区域。

Isolation of plane SV waves by discontinuous barriers composed of several rows of cylindrical cavities

Adopting the conformal mapping method of complex functions and the expansion method of wave functions and considering the free boundary conditions of cavities and zero stress in soil around cavities,the theoretical solutions were obtained about the multiple scattering of incident plane SV waves by discontinuous barriers composed of several rows of cylindrical cavities. By examining the normalized displacements which are the ratios of the displacements caused by incident and scattering SV waves to those only by incident SV waves,the isolation effect of the barriers composed of one or more rows of cylindrical cavities was analyzed,and some important conclusions were drawn out: the isolation effect of the barriers composed of two,three or more rows of cylindrical cavities is better than those composed of only one row; when the frequencies of the incident SV waves are lower,the isolation effect of the barriers composed of two rows of parallel positive aligned cylindrical cavities is better,while when the frequencies are higher,the isolation effect of two rows of parallel staggered cylindrical cavities is better; the isolation effect of the barriers composed of three rows of cylindrical cavities is better than those of two rows,and when the incident frequencies of SV waves are higher,the isolation effect in about 3/4 area behind the barriers is obvious and is more than 60%; as to the barriers composed of one or more rows of cylindrical cavities,when the incident frequencies of SV waves are higher,the isolation effect in the area near the edge of the barriers is better than that in the middle.