钉形水泥搅拌桩单桩承载性状试验研究

TEST ON BEARING CAPACITY OF SINGLE T-SHAPED MIXING CEMENT PILE

结合深厚软土地区地基加固工程,通过钻芯试验和单桩(复合地基)静载荷试验研究钉形水泥搅拌桩的承载特性。钻芯试验表明,粧身水泥土强度随深度增加而逐渐减小,深部水泥土强度随龄期增长较明显。单桩(复合地基)静载荷试验研究表明,扩大头部分的桩身轴力衰减速度比桩身下部快,桩深10m处轴力非常小。单桩复合地基静载荷试验的桩身轴力衰减速度更快,而复合地基桩土应力比随荷载的增大而逐渐减小并趋于稳定。

Based on laboratory mixture ratio test,core drilling test and static load test of single pile(composite foundation)for T-shaped deep mixing cement pile in deep soft soil,its bearing capacity and the load transfer mechanism are investigated.By the core drilling test under different curing,it is shown that the cemented-soil strength decreases with the depth,and the deep cemented-soil strength grows rapidly with the time.Through the single pile(composite foundation)static load test,it is concluded that the axial forces decrease with depth,and its reduction rate for enlarged cap is greater than one for ordinary pile section.There is little axial force of pile at 10 meters depth.Comparison with the single pile static load test,the axial force along pile body in the static load test for single pile composite foundation decrease more quickly.The stress ratio of pile and soil reduces with the increasing load,and tend to a constant value.