某高速铁路动车段地基处理沉降研究分析

Comparison of Foundation Treatments of a Certain High Speed Railway EMU Depot Based on Settlement Analysis

为满足某境外高速铁路动车段淤泥质土地基的不同沉降要求,选出最优工程方案,首先根据工程地质条件、铁路等级以及工期等因素筛选适用于该动车段的地基处理方法;之后,根据地层条件和地基处理工程经验拟定各区域加固深度;最后,通过造价比较,确定各区域的最佳地基处理方案。研究分析结果表明:适用于该动车段淤泥质土的地基处理方法有水泥土搅拌桩、预应力管桩以及塑料排水板。沉降要求为300 mm的区域Ⅰ,采用长16 m、间距1. 2 m、桩径0. 5 m的水泥土搅拌桩复合地基;沉降要求为15 mm的区域Ⅱ,采用长24 m、外径0. 4 m、桩间距1. 3 m的预应力管桩;沉降要求为400 mm的区域Ⅲ,采用深度为14 m、间距1. 0 m的塑料排水板结合堆载预压。

In order to meet different settlement requirements for the silt foundation of a certain oversea highspeed railway EMU depot and select the optimal engineering plan,this paper has done the main work as follows. First of all,according to the engineering geological conditions,railway grade and construction period,the foundation treatment methods applicable to the EMU depot are screened. Then,foundation reinforcement depth of each area is drafted based on the formation conditions and engineering experience of foundation treatment. Finally,the optimal foundation treatment plan for each area is determined by comparing project costs of each plan. The result of this research shows that the foundation treatment methods suitable for the silt foundation of this EMU depot include cement soil mixing pile,prestressed RC pipe pile and plastic drainage board. Area Ⅰ with a settlement requirement of 300 mm adopts a composite foundation of cement-soil mixing piles with a length of 16 m,a spacing of 1. 2 m and a pile diameter of 0. 5 m;area Ⅱ with a settlement requirement of 15 mm adopts prestressed RC pipe piles with a length of 24 m,an outer diameter of 0. 4 m and a pile spacing of 1. 3 m;areaⅢ with a settlement requirement of 400 mm adopts plastic drainage boards with a depth of 14 m and a spacing of 1. 0 m combined with preloading.