驻信高速公路改扩建工程复合地基加固沉降控制技术研究

发布时间：2018-08-27 10:44

【摘要】：近年来我国已对多条高速公路做了拓宽改造工程,发现普遍存在新老路基差异沉降问题,产生了较多的病害,严重影响了道路的结构性与功能性要求。高速公路改扩建后差异沉降虽不可避免,但我们可以采用一定的方法减少路基差异沉降,而差异沉降主要是由新路地基过大的沉降引起的。因此有必要对路基差异沉降及其控制技术进行研究。本文以水泥搅拌桩、CFG桩等复合地基在驻信高速公路改扩建工程中的应用为契机,研究复合地基在改扩建工程中的应用情况和应用效果,并对高填软基、桥涵路基等容易产生较大差异沉降的路段进行大量的沉降监控,以控制沉降和分析新路基的沉降规律,并用曲线拟合的方法对新路基工后沉降进行了较为准确的预测研究。主要内容如下:(1)简要介绍了水泥搅拌桩、CFG桩在工程中的应用情况,并介绍了其在驻信高速公路改扩建工程中施工技术。对水泥搅拌桩和CFG桩大量的工后检测数据进行分析,得出了保证施工质量的控制因素。(2)在驻信高速公路改扩建工程中布置了大量的沉降板、横剖管以及测斜管等变形观测器材,对观测数据进行了详细的分析。得出了由于新路基的沉降受各种因素的影响导致了新路基沉降与前人理论研究结果有很大的不同。实际施工过程中的复杂性导致无法根据沉降大小判断复合地基处理断面相对于未做地基处理的断面具有较好的改善效果。(3)分析了未作处理与复合地基处理断面的累积沉降-时间曲线,得出了复合地基处理断面可以使路基沉降更快稳定的结论。根据老路硬路肩累计沉降-时间曲线,发现新路基填筑时老路硬路肩沉降有明显的上升现象,填筑完成后开始沉降且慢慢趋于稳定,并对这一现象做了分析,但最终沉降小于新路基沉降。(4)沉降观测是为了控制路基的施工质量并根据一定的数学方法预测工后沉降,本文参考大量的资料分析了有限元法、动态预测法以及曲线拟合法,发现曲线拟合法在本文中应用较为合适,且应用较为简便,预测结果较为理想。
[Abstract]:In recent years, China has carried out widening and rebuilding projects on many expressways, and found that there are common problems of differential settlement of new and old subgrade, which have caused more diseases and seriously affected the structural and functional requirements of roads. Although differential settlement is inevitable after highway reconstruction and extension, we can adopt certain methods to reduce the differential settlement of roadbed, which is mainly caused by the excessive settlement of the new road foundation. Therefore, it is necessary to study the subgrade differential settlement and its control technology. In this paper, the application of cement mixing pile and CFG pile in the reconstruction and extension project of Jianxin Expressway is taken as the turning point, the application and effect of composite foundation in the reconstruction and extension project are studied, and the high filling soft foundation is also studied. In order to control the settlement and analyze the settlement law of the new subgrade, the settlement of the bridge and culvert subgrade, which is easy to produce great difference settlement, is monitored, and the settlement after construction of the new roadbed is predicted and studied accurately by the method of curve fitting. The main contents are as follows: (1) the application of cement mixing pile and CFG pile in the project is briefly introduced, and the construction technology of the CFG pile in the reconstruction and extension project of the Jiaxin Expressway is introduced. Based on the analysis of a large number of post-construction test data of cement mixing pile and CFG pile, the control factors to ensure the construction quality are obtained. (2) a large number of deformation observation equipment, such as settlement plate, cross-section pipe and inclined pipe, are arranged in the reconstruction and extension project of Jianxin Expressway. The observation data are analyzed in detail. It is concluded that the settlement of the new subgrade is greatly different from that of the previous theoretical research because of the influence of various factors on the settlement of the new subgrade. Because of the complexity of the actual construction process, it is impossible to judge the treated section of composite foundation according to the settlement size. (3) it is analyzed that the treated section of composite foundation and untreated section of composite foundation have better improvement effect than that of untreated section of foundation treatment. Cumulative sedimentation time curve, It is concluded that the composite foundation can make subgrade settlement faster and more stable. According to the cumulative settlement-time curve of the hard shoulder of the old road, it is found that the settlement of the hard shoulder of the old road increases obviously when the new roadbed is filled, and the settlement begins to settle and tends to stabilize slowly after the completion of the filling, and this phenomenon is analyzed. But the final settlement is smaller than the new subgrade settlement. (4) the settlement observation is to control the construction quality of the subgrade and predict the post-construction settlement according to certain mathematical methods. This paper analyzes the finite element method, the dynamic prediction method and the curve fitting method with reference to a lot of data. It is found that the curve fitting method is more suitable and convenient to be used in this paper, and the prediction result is more ideal.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U418.8;U416.1

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