水泥土复合地基在快速铁路上的应用

Application of Cement Composite Foundation to Express Railway

水泥搅拌桩已经是一种较为成熟的地基处理形式，加上其设置于桩顶的“增强体”即构成水泥土复合地基，尤其适用于黏土、淤泥质黏土、粉土和砂土质软弱地基加固。东北东部铁路通道丹大快速铁路前阳至庄河段DK33＋097．52～DK37＋478．68段工程部分段落为软土地基，0—9m以内地层较松散，主要成分为淤泥质粉质黏土、稍湿呈浅黑色粉土等，不能满足路基工程设计基底承载压应力。鉴于此，对软土地基段落采用水泥搅拌桩进行加固，桩顶设0．5m厚碎石垫层，垫层内夹铺一层抗拉强度为120kN／m的单向拉伸土工格栅，形成水泥土复合地基。为确保软基加固质量，采用了“两喷六搅”水泥搅拌桩施工工艺，处理结果十分理想，满足设计和规范要求。

The cement pound foundation with mixed pile has been a mature ground treatment method, which is composed of the cement com- ＂reinforcements＂ on the top of the pile, especially suitable for reinforcement of clay, mucky clay, silt and sandy soil soft foundation. Some subsections of Qianyang-Zhuanghe section DK 33 ＋ 097.52-DK 37 ＋ 478.68 of Dandong-Dalian High-speed Railway in the east of Northeast China are soft foundation, where the stratum within 0 9 meter is composed of loose foundation bottom in subgrad mucky clay and li e work design. In t-black slight-wet silt, which cannot satisfy the compressive stresses of ew of this, cement mixed piles are used for reinforcement in the soft ground, and 0. 5 m thick crushed stone cushion is set on the top of the pile and in the cushion a layer of uniaxial tension geogrid with tensile strength of 120 kN/m is laid to form the cement compound foundation. To ensure the reinforcement quality of soft soil foundation, ＂two-jet ＆ six-mixed＂ cement mixing pile construction process is used, and the results are very satisfactory and meet the design and specification requirements.