This paper presents a theoretical study on the ground vibration isolation cfficiency by multi-rows of piles as passive barricr in a three-dimensional context. Integral equations governing Rayleigh wave scattering are derived according to the Green's solution of Lamb problem. The integral equations are solved accuratcly and efficently with an iteration teehnique. They are used to predict the complicalled Rayleigh wave field that is generated by a number of irrcgular scatterets embedded in an elastic half-solid. The method is Vcrified with a numberial solution available in the literature for a simplified Rayleigh wave scatteing problem. Passive isolation effectiveness of ground vibration with two or three rows of small piles is further studied in detail Effccts of relevant parameters on the effectiveness of vibration isolation are analyzed and presented. 2006 Elsevier Ltd. All rights reservd.

Magnetic-levitating train is a new typa of ground transportation means. Tha first commerciai magnetic-levitation line in the world has been built in Pu Dong of Shanghai, China However, to the authors' knowledge, few tests and analyses about ground vibration and the influences on environment induced by actual magnetic-levitatlng train have been reported in the open literature. In this paper, the large-scale test results about the magnetic-train in Shanghai are reported. The characters of grand vibration and wave propagation induced by magnetic-train at different speeds are studied. The results indicate that the ground vibration by magnetic-levitating train is less than that caused by wheel-track train. The dramatic increase of ground vibration, which is existed in wheel-track train when the speed exceeds Raylaigh wave, was not found.

The propagation of Man-Made environmental vibration at near-field and far-field were expounded in the paper respectively. The near-field wave is mainly caused by source energy mechanism and the far-field wave energy is lost due to mainly the proporty of soft. Meanwhile real terrain is not perfectly smooth. The barders, the effective and the reliable measures, were used to control environmental vibration. It is a practical and conomical way. The beneficial result of the barriers only when the found theory of wave propagation and the theory of screening of baeders are reasonable plan. Theory of design and calculation of vertical and horizontal barriers and the cause that some barrier engineering which were designed in the screening inefficiency or anti-effictency caused by neglecting and mistmderstandthg the principle of shield of the battier were presented in the paper. The poablem of attached environmental vibration induced by barrier was installed which will change the frequency at the ground is also presented. These case histories, which have alredy been used effectively on controlling Man-Made environmental vibration by baffler, were reported in the paper.

从Lamb问题的基本解出发，通过对弹性波散射问题的积分方程进行复杂的数学变换和推导，得到了一个适合于瑞利波散射问题的积分方程的简单表达式，通过迭代求解这个表达式即可解决多个不规则异质体引起的瑞利波散射问题。实例证明本文方法收敛速度非常快，通常只需迭代3～4次即可得到精确的解答。

视桩为弹性半空间中的异质体，以瑞利波散射的积分方程为基础，首次对多排桩屏障的远场被动隔振效果进行了三维分析。详细讨论了影响隔振效果的几个主要参数，指出非连续排桩屏障隔振起到的是整体屏蔽作用。研究表明，影响多排桩屏障体系隔振效果的厚度主要取决于桩的排数，与桩的截面尺寸关系不大；密布小截面多排桩隔振效果与空沟和填充沟相当；桩的排距对隔振效果影响小；每一排桩的桩间净距是影响隔振效果的重要参量，为了获得满意的隔振效果，应控制相邻桩的桩间距足够小。最后，通过工程实例验证了多排桩的隔振效果。

把填充沟看作存在于弹性半空间的异质体，运用瑞利波散射的积分方程，对填充沟连续屏障远场被动隔振进行了三维分析，详细讨论了影响隔振效果的几个主要参数。研究表明，刚性材料比柔性材料具有更好的隔振效果，在隔振设计时应选择刚性屏障材料；填充沟的深度在一倍瑞利波波长内对隔振效果有较大影响，并且与宽度一起决定其隔振效果，但当屏障深度超过一倍瑞利波波长后，屏障深度对隔振效果的影响很小。

大型高速滑坡在启程活动阶段中，由于锁固段突然被剪断，高度集中的剪应力突然被释放，常出现孔隙水压力突然增大；同时，饱水的滑带由于强烈的高速摩擦，使滑面附近产生高温，并使滑带水突然汽化，产生巨大的水汽化压力；孔隙水压力与水汽化压力耦合，使作用在滑面上有效应力减小。这两种流体动力学现象是大型高速滑坡产生启程剧滑的重要原因。通过三轴剪切试验，探讨了滑带孔隙水压力与剪切速率的关系，导出了大型高速滑坡启程活动阶段滑带孔隙水压力的计算公式。详细地研究了大型高速滑坡启程活动阶段滑面瞬态温度场的变化规律，导出了滑面温度变化的方程式，计算了云南头寨沟滑坡启程活动阶段由于强烈高速摩擦产生热量的传导深度，进一步对该滑坡启程活动阶段滑带孔隙水汽化效应进行了研究。

根据同一场地砂卵石层中一组土的深层静载荷试验、一组纯摩擦桩和两组原型扩底墩的竖向承载力静载试验，分析了埋深在6.20～6.75m处的扩底短墩的荷载传递性状。结果表明，可用直接试验法和间接试验法确定扩底墩的竖向承载力。以卵石层为持力层的S3试验墩的极限承载力为7250kN，其中端阻力达6890kN，占95%；以砂层为持力层的S2墩的极限承载力为2330kN，端阻力占85%。当墩顶仅沉降1.46mm 左右时，S3、S2墩侧摩阻力已充分发挥；在端阻力充分发挥时，S3、S2墩顶沉降则分别达92.64mm和21.07mm。直径相同时，扩底桩的竖向承载力远大于纯摩擦桩和直身墩。

饱和粘土在不排水循环荷载作用下强度会发生衰减，建立在粘土地基上的建筑物和填土道路在地震过程中有时会遭受破坏。传统有效应力摩尔-库仑强度理论不能正确确定循环荷载作用下粘土的不排水强度。在超固结粘土不排水强度计算的基础上，引入循环荷载作用损伤因子，提出循环荷载作用下饱和粘土不排水强度计算方法以及参数的确定方法。通过试验验证，所提出的方法是合理的。该方法为循环荷载作用下粘土地基的不排水强度和稳定性预测提供有效的途径。

文克尔地基模型广泛应用于弹性地基梁、板的设计计算，但由于该模型过于简化，不能正确反映地基土的工程性质。为此，提出了一种改进的双参数层状地基模型。该模型是Vlazov模型的延伸和发展，由一系列的弹性层组成，对每一层的应力应变分布做了一定的假设。通过积分变换的方法，可以求出该模型每一层表面位移与力的关系，进而形成层刚度矩阵。按照有限元法的原理，将每一层的刚度矩阵凝聚成总体刚度矩阵求解，与Vlazov 模型计算结果的比较，证明该方法是正确的，还得到了荷载作用于层状地基模型内部的解，为双参数层状地基模型用于桩基分析打下了理论基础。