戈壁滩高速铁路强夯地基及静载试验研究

Static Load Experiment Study on Dynamic Compaction Foundation for Express Railway in the Gobi Desert

首次对戈壁滩在建的兰(州)新(疆)高速铁路的玉门镇段的4.40 m厚不均匀圆砾土层路基,采用强夯地基处理,取夯锤直径2.50 m,,锤高0.70 m,锤重267.0 kN,提升高度大于10.00 m,强夯能量大于2 670 kN.m;点夯三遍,满夯两遍,强夯地基下沉量达0.27 m,改善了圆砾土的不均匀性,强夯地基强度明显提高;强夯结束15天后,采用动力触探、静载试验对强夯地基进行承载力检测,动力触探深度4.70 m,静载试验取钢质正方形承压板宽度2.20 m×2.20 m,最大荷载1 782.4kN,检测影响深度达4.40 m,静载承载力特征值184 kPa,满足设计180 kPa的要求。

The inhomogeneous gravel soil subgrade with the thickness of 4. 40 m in the Yumenzhen Section of Lanzhou-Xinjiang Express Railway under construction in the Gobi Desert is treated by dynamic compaction foundation firstly. With the rammer diameter of 2. 50 m, rammer height of 0. 70 m, rammer weight of 267 kN, lifting height more than 10. 00 m, and dynamic compaction energy more than 2670 kN ~ m, point compaction is carried out three times and full compaction two times. The foundation settles up to 0. 27 m, thus the inhomogeneity of the gravel soil is improved and the strength of the foundation is increase significantly. After 15 days from dynamic compaction, dynamic penetration and static load experiments are carried out to detect the bearing capacity of this foundation. With the dynamic penetration depth of 4.70 m, and the width of steel square bearing plate of 2. 20 m x 2. 20 m, maximum load of 1782. 4 kN, detecting depth up to 4. 40 m in static load test, the characteristic value of the static 180 kPa. bearing capacity is 184 kPa meeting the design requirement of