Based on the discussion above , firstly in this article , it researches the deformation situation of pile soft soil flexible foundation of djcm pile composite ground under flexible foundations and the effecting law to the mechanic characteristics of soil while making pile through the model test in library 基于上述考虑，本文首先通过室内模型试验，研究了柔性基础下水泥粉喷桩地基中桩、桩间土和柔性基础(试验中为砂垫层)的变形情况，以及水泥粉喷桩在成桩过程中对桩间软土物理力学性质的影响规律。
This paper introduces the limit - destruction theory to study and analyze the function - mechanism of sand cushion in the collective function of the piles and the earth , and then brings forward the regulating - equation of the stress ratio between the up - pile - soil and the top of pile concerning the sand cushion . its final calculating result basically tallies with the practical function conditions . this provides an alternative approach to the study of sand cushion 4在复合地基桩、土共同作用中，垫层的作用和机理，本文引入极限破坏理论对砂垫层作用机理进行分析研究，提出砂垫层的桩顶桩土应力比协调方程，其计算结果与实际作用情况较吻合，为砂垫层研究提供了一种思路。
A certain thickness of sand cushion of a certain size or gradation is paved between the foundation and ground in this new method . when earthquake happens the sand cushion will have plastic shearing strain , reducing the input of high frequency volume , thus consume the earthquake energy form substrate . it is showed in shaking table experiments that there is relevant slippage between foundation and sand cushion , which can prevent the seismic energy from being passed to the above structure and thus reduced the seismic role for the above structure 在建筑物的基础与地基之间铺设一定厚度、某种单一粒径或级配砂垫层，在地震作用时砂垫层发生的塑性剪切变形，减少地震波高频分量的输入，从而消耗了下层传来的地震能量；振动台试验表明，当振动发生时，基础与砂垫层之间有明显的滑移产生，这就对地震能量向上部结构的传递起到了隔断作用，因而对上部结构起到了减震作用。
And the confinement effects ( lateral restrained ) of the sand - mat and reinforced - mat with loading are presented , with their differences after a period of loading also illustrated by comparing performances with each other , which will be a great progress for calculating the additional settlement resulting from shear deformation . 3 同时，解释了砂垫层和加筋垫层(作为具体层位)的侧限作用随外载增加的变化规律及其差异原因；并由此分析了影响因素对加筋垫层、砂垫层影响程度的差异及其变化规律，将剪切变形引起的“附加沉降”计算方法的建立推进了一步。
