武广客运专线路基沉降监测系统与沉降预测

Subsidence Monitoring System and Subsidence Prediction for the Subgrade of Wuhan-Guangzhou Passenger Dedicated Line

研究目的：目前对路基沉降理论尤其是柔性荷载下复合地基的沉降机理研究的十分有限，常规的理论计算结果与实际情况存在较大差异。以武广客运专线典型路基断面为例，采用CFG桩复合地基处理方法，对路基沉降变形进行监测，结合实测沉降曲线对沉降规律进行探索，并利用曲线拟合法对路基沉降进行预测，通过研究与分析，了解和掌握柔性荷载下CFG桩复合地基的沉降特性，为工程建设提供借鉴。研究结论：通过对武广客运专线典型路基沉降变形监测的研究，和利用曲线拟合法对路基沉降进行的预测得出以下结论：路基中心总的沉降量大于左右路肩沉降，路基中心总沉降曲线与左右路肩沉降曲线斜率变化基本一致；沉降量最大值不是路基中心，而是距中心大约1～2m处。双曲线拟合法与指数曲线拟合法预测结果偏大，三点法预测结果偏小，Asaoka法介于两者之间，对观测时间没有特殊要求，其预测值较为准确。采用CFG桩复合地基处理方法能很好的控制沉降.

Research purposes： Nowadays the study on the subgrade subsidence theory, especially on the subsidence mechanism is done not much. There is a big gap between the calculated result with common -used theory and the real situation. To the subgrade section of Wuhan - Guangzhou Passenger Dedicated Line, CFG pile was used to treat the subgrade and the subgrade subsidence deformation was monitored for seeking the subsidence law with the subsidence curves and predicting the subsidence with the curve fitting method. Through the study and analysis, the subsidence behaviors of CFG pile composite subgrade are known, so the reference can be offered to the construction. Research conclusions：The following conclusions can be obtained from the study on subgrade subsidence deformation and the prediction of the subgrade subsidence of Wuhan - Guangzhou Passenger Dedicated Line with the curve fitting method： The total subsidence in the subgrade center is bigger than that in the right and left subgrade shoulders and the total subsidence curve in the subgrade center is basically consistent with the grade rate of curve of right and left subgrade shoulders. The biggest subsidence is not in the subgrade center, but in the place 1 -2 m away from the subgrade center. The predicted results with double curve fitting method and exponential curve fitting method are over big and the predicted result with three - point method is over small. However, the predicted result with Asaoka method is mediated with no especial requirement of prediction time and high accuracy. The subsidence can be controlled well by adopting CFG pile composite foundation.