高速铁路路基基底盐渍土抗溶陷措施

Resist Collapse Measures of Saline Soil Under High Speed Railway Subgrade

盐渍土的溶陷变形可能造成线路不平顺性加剧,不利于高速铁路的安全运营。而水分是影响盐渍土地基溶陷的主要因素。为研究高速铁路路基基底盐渍土的抗溶陷措施,开展了不同反压护道宽度与垂直防渗深度的渗流计算。结果表明:不同工况下,体积含水率增量沿地基深度方向均呈先增大后逐渐减小趋势,孔隙水压力增量沿地基深度方向呈衰减变化;路基坡脚外增设反压护道及垂直防渗措施均可有效防止基底浅层土的体积含水率增大,路基基底的防渗效果与反压护道宽度及垂直防渗深度成正比;建议采用"3 m宽反压护道+4 m深垂直防渗"作为徳伊高速铁路路基基底盐渍土的抗溶陷措施。

The collapse deformation of saline soil may increase the irregularity of the line, which is harmful to the safety operation of high speed railway. And the water is the main factor affecting the collapse deformation of saline soil foundation. In order to study the resist collapse measures of saline soil under high speed railway subgrade, the seepage calculations of saline soil with different widths of back berm and different depths of vertical anti-seepage were carried out. The results show that the increment of volumetric water content increases first and then decreases gradually along the depth of the foundation, and the increment of pore water pressure decreases continuously along the depth of the foundation. Measures of back berm and vertical anti-seepage can be designed to decrease the increment of volumetric water content of shallow layer, and anti-seepage effectiveness is proportional to the widths of back berm and the depths of vertical anti-seepage. The 3 meter in width of back berm and 4 meter in depth of vertical anti-seepage are suggested to resist collapse measures of saline soil under subgrade of Tehran- Isfahan high speed railway.