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郑西客运专线路堤工后容许沉降量为15mm,湿陷性黄土区路堤地基处理的沉降控制是关键性技术难题,为此,选择湿陷性黄土代表性地段进行了不同地基处理措施路堤工程沉降观测试验研究。研究结果表明,路堤本体的压缩沉降量只有3mm,并在路堤竣工后的15d内趋于稳定,路堤沉降主要由地基沉降控制,而地基沉降则决定于3种不同地基处理措施层以下土层的沉降量大小。在沉降量大小、地基处理和浸水效果方面,22m深湿陷性土层全部处理的柱锤冲扩桩区段最好,15m深湿陷性土层的挤密桩区段较好,6m深湿陷性土层的强夯区段最差,而且采取合理的防排水措施防止坡脚附近积水浸泡非常必要。采用双曲线法、三点法和Asaoka法预测结果的平均值作为路堤的最终沉降量,柱锤冲扩桩区段、挤密桩区段的路堤分别需要恒载预压5个月、8个月便可卸除荷载铺设无碴轨道,强夯区段路堤的预压荷载可能需要持续很长的时间。
The allowable settlement of post-embankment of Zheng-Xi Passenger Special Line is 15mm. The settlement control of embankment foundation in collapsible loess area is the key technical problem. Therefore, the settlement of embankment with different foundation treatment measures is selected for the representative sections of collapsible loess Observational experimental research. The results show that the compressive settlement of embankment body is only 3mm and stabilized within 15 days after the completion of embankment. The settlement of embankment is mainly controlled by foundation settlement, while the settlement of foundation is determined by the treatment of soil below three kinds of foundation treatment measures The size of the settlement. In the aspects of settlement amount, foundation treatment and water immersion effect, the section of piling hammer pile fully processed with 22m deep collapsible soil layer is the best, the section of compaction piles with 15m deep collapsible soil layer is better, the 6m deep wet The strong compaction section of the collapsed soil layer is the worst, and it is very necessary to take reasonable measures to prevent draining water and prevent soaking water near the foot of the slope. Using the average of the hyperbolic method, the three-point method and the Asaoka method as the final settlement of the embankment, the embankment of the column with hammer-pumped pile and the embankment of the compacted pile section need to be preloaded for 5 months and 8 months The ballastless track can be unloaded and the preload of the embankment in the dynamic compaction section may take a long time.