旋喷桩在既有线顶进箱涵中的应用.docVIP

摘要 在框架顶进中，由于不良地基的影响，需要对路基进行加固。特别是繁忙和提速后的线路要求顶进施工时限速不低于60 km/h，对路基加固提出更高要求。高压旋喷桩由于其自身的诸多优点，广泛应用于修建框架桥时加固路基。 本文结合萧山金城路东伸下穿铁路立交桥工程，分析了工程地质资料，对工程施工的特点、难点以及工程的总体布置情况进行了扼要说明，同时对施工过程中的基础加固、基坑围护进行了详细的论述，重点介绍了高压旋喷桩的施工工艺，也对地道桥箱体顶进施工的总体安排及详细施工过程作了简要的阐述。对50组高压旋喷桩进行了试验，无侧限强度做7、14、28天三种龄期试验，抗剪强度做28天龄期试验，给出了钻芯检测成果表。 利用ANSYS有限元软件对旋喷桩加固地基后顶进箱涵的力学特性进行分析。地道桥空间模型和平面模型分别计算得到的横向弯矩基本相同，考虑横向主筋配置时，仅采取平面模型计算就可以得到较好的结果。纵向弯矩与横向弯矩的比值，无论是双孔还是单孔，随着地道桥长度的增加，横向弯矩占纵向弯矩比值逐渐增大。 关键词：旋喷桩；顶进施工；地基加固；有限元 Abstract Because the influence of bad ground need be reinforced the roadbed, it is necessary to reinforce the ground base in frame jacking. The speed limit was not less than 60 km/h when especially busy circuit with the back of raising speed required the top to advance to construct, proposed requirements at the higher level to formation strengthening. The high pressure cement injection piles use reinforcement road bed when building the frame bridge is extensively applied to its self a great deal of merit. This paper combines Xiaoshan Jin Cheng way east and wears railway overpass engineering under stretching, has analysed the engineering geology material, has carried out brief explanation to the general arrangement circumstances of characteristics, difficult point and the engineering of construction, go along with the strengthening of foundation in the construction course, foundation ditch besides and carried out detailed argumentation, has introduced the construction technology that the high pressure cement injection piles soon with an emphasis, and also arrange the genuine bridge box top totality that advances the construction and concise and to the point exposition has been done to detailed construction course. The 50 groups high pressure cement injection piles are tested, it is experimental that 7,14,28 days three kinds of length of times are done to no lateral confinement intensity, and it is experimental that the 28 days length of time is done to the shearing strength, has provid