高速铁路深厚软土地基物理力学特性分析及沉降控制

为研究东北地区高速铁路软土地基路基物理力学特性及其沉降控制方法,通过物性参数试验、无侧限抗压强度试验、直接剪切试验以及固结试验等,并结合工后沉降检算,提出适用于该片区的地基加固手段。研究表明:(1)研究区域软弱夹层分布在地表8 m以下,厚度为4~8 m,液性指数随深度逐渐下降,在14 m处降至最低;(2)0~8 m深度范围内,无侧限抗压强度、黏聚力、内摩擦角、压缩模量等指标随深度变大逐渐下降,深度8 m以下,强度指标随深度加深不断上升,在14 m深度处达到峰值;(3)桩长为8~16 m时,工后沉降随着CFG桩长增大线性降低,桩长增至16 m时,工后沉降降幅约为70%,为该区域最优桩长。

Analysis of Physical and Mechanical Properties of Deep Soft Soil and Settlement Control of High-speed Railway

In order to study the physical and mechanical properties and settlement control methods of soft soil subgrade of high-speed railway in Northeast China,physical parameter test,unconfined compressive strength test,direct shear test and consolidation test were conducted.Combined with the post-construction settlement calculation,a foundation reinforcement method suitable for this area was proposed.The results show that:(1)the weak intercalation in the study area was distributed 8m under the surface,with the thickness of 4~8 m,and the liquid index decreased gradually with the depth,and reached the lowest at 14 m;(2)in the range of 0~8 m,the strength indicators continuously increased with the depth under 8m,reaching the peak at the depth of 14 m;(3)when the pile length was 8~16 m,the post construction settlement decreased linearly with the increase of CFG pile length,when the pile length increased to 16 m,the post construction settlement decreased by about 70%,which was the optimal pile length in this area.