论强夯地基的双层构造问题

On the Double-layer Subsoil in Dynamic Compaction

作者认为强夯使地基具有AB层即双层构造。根据实际资料说明。强夯地基的上部(即A层)和下部(B层)各具特点,自成独立系统。夯击过程动应力水平为临界值的那个深度位置即是AB两层的交界。A层属强夯实区,土层变形大且大部分位置经历过“破坏”夯实过程;B层属弱夯实区,变形小且不论击次增加到多大亦不会进入破坏阶段。A层是良好持力层,只要设计合理,施工得当,此层夯后承载力的增加值同夯前土层原有承载力相比,占明显比例;B层承载力大体维持土层原有水平,有时有提高或降低。从实用观点看,主要应查清A层情况及其底界深度;对B层的了解一般情况下达到一定深度即可。

The subsoil formed a double-layer structure during the dynamic compaction. Summarized from extensive in-situ test results, both the upper layer(A) and lower layer (B) have their own distinctions and independent each other. The interface of A and B occures in the location of critical level of dynamic stress during the compaction, layer A is the area of densely compacted, most of the particles have a large deformation imparted by the high destructive stress,whereas layer B pertains to poorly compacted area with the character of small deformation and doesn't lead to collapse with regardless of the number of blows If the proper design and a treatment procedure are induced in the compaction, the upper can achieve a good bearing layer, which has a exponent increasing in bearing capacity value compared with that of to be treated, the bearing capacity of lower layer approximately to keep the average level of before treaded soil eventhough with little fluctuated. From the practical point of view, the princple work is to entirely investigate the character and the thickness of upper layer, and to get a general knowledge to the difinite depth of lower layer.