水泥土搅拌桩搅拌均匀性的电阻率评价方法

采用电阻率测试方法,以常规水泥土搅拌桩和双向水泥土搅拌桩为例,对水泥土搅拌桩芯样电阻率进行测试.通过对其电阻率及其表征水泥土微观结构的结构因子、形状因子和各向异性指数的定量分析,阐述了水泥土搅拌桩在水平方向和沿桩身方向的均匀性;通过与搅拌桩桩身标贯击数和无侧限抗压强度等宏观力学指标对比,验证了利用电阻指标评价水泥土搅拌桩搅拌均匀性的科学性与可行性.结论表明:常规水泥土搅拌桩搅拌不够均匀,桩身水泥土的微观结构、物理力学性质随深度增加变差,表现出方向上的差异性.双向水泥土搅拌桩搅拌均匀,桩身水泥土的微观结构、物理力学性质沿桩身分布均匀.取芯和标贯试验论证了上述结果.

Electrical resistivity evaluation method to homogeneity of soil-cement deep mixing column

The homogeneity characteristics was studied by means of electrical resistivity measurement with bi-directional cement-soil deep mixing column and traditional deep mixing column core samples;The homogeneity of column was analyzed quantitatively with the electrical resistivity,the formation factor,the shape factor and the anisotropy factor of core samples along the column.It's shown that electrical resistivity and derived parameters can be used to evaluate the homogeneity of column quality in view of SPT(standard penetration test) blow counts and unconfined compression strength along the column.It is indicated that the quality,microstructure,and isotropy of bi-directional cement-soil deep mixing column are far superior to the traditional deep mixing column.In situ SPT tests on columns and unconfined compressive strength of core samples are consistent with the above results.