Mass permeability concept in the analysis of treated ground with sand drains
Mass permeability concept in the analysis of treated ground with sand drains
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沙漏处理过的地面分析中的质量渗透率概念
DOI：
10.3208/sandf.35.43
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发表时间：
1995
影响因子：
3.7
通讯作者：
M. Nozu
中科院分区：
文献类型：
--
作者：
A. Asaoka;M. Nakano;G.S.K. Fernando;M. Nozu
当考虑路堤荷载作用下的软土地基时，沉降特性受质量渗透率和荷载强度的影响，而荷载强度由初始不排水承载力来归一化。利用这两个参数，粘性土地基的固结沉降特性可用一组S曲线来表示。影响残余沉降的质量渗透率范围被限制在一个很窄的范围内。对于路堤地基，当这两个参数已知时，可以唯一地确定其沉降性状。用宏观单元法研究了砂井对粘土地基质量渗透性的改善作用(Sekiguchi等人，1986)。砂井的质量渗透性是未处理地基的30-300倍。上述发现被应用于两个案例研究。在第一种情况下，当地基在高荷载作用下用砂井处理时，发现只有沉降观测可以用来评估该地基中砂井的有效性。另一种情况是珊瑚土，与普通粘土相比，珊瑚土表现出高渗透性和高的初始不排水承载力。残余沉降量的显著减少证明了该地基砂井的有效性。
When a soft clay foundation under embankment loading is considered, settlement behavior is affected by the mass permeability and by the magnitude of applied load intensity, which is normalized by the initial undrained bearing capacity. Using these two parameters, the characteristic consolidation settlement behavior of a clay foundation can be represented by a family of S shaped curves. The range of mass permeability affecting residual settlements is confined to a narrow limit. For an embankment foundation, when these two parameters are known, settlement behavior can be determined uniquely. The effects of improvement of mass permeability by sand drains on a clay foundation are investigated using the macro element method (Sekiguchi et al., 1986). The sand drains improve the mass permeability to 30-300 times that of the non-treated ground. The above findings are applied to two case studies. In the first, where the ground is treated with sand drains under a high applied load it is found that only settlement observations can be used to assess the usefulness of sand drains in this ground. The other case is on coral soils which exhibit high permeability and a high initial undrained bearing capacity compared with common clay deposits. The effectiveness of sand drains in this ground is evidenced by a significant decrease in residual settlement.