大风、高温差条件下高铁路基沉降自动观测仪器与评估方案研究

无砟轨道铺设前,应对线下工程沉降做系统评估,以确认工后沉降和变形能否符合设计要求。兰新铁路第二双线严酷的自然条件下,既有的路基沉降监测与评估方案难以达到规范所要求的测试精度、频次以及评估的有效性。针对该问题,研发了多点静力水准沉降观测仪,选择代表性工点对沉降变形评估方案进行研究。研究结论为:(1)室内检定结果表明所研制的多点静力水准沉降观测仪测试绝对误差小于1.0 mm,而现场测试数据还未能达到室内检定的测试精度;(2)对兰新铁路第二双线特殊气候条件下的沉降观测数据,采用指数曲线法和Asaoka法可以得到相关系数更高的沉降预测结果;(3)兰新铁路第二双线路基沉降评估工作中,将现行规范要求的曲线回归相关系数由0.92放宽至0.85更为可行。

Research on Auto-observation Instrument for Subgrade Settlement Deformation Subject to Strong Wind and High Temperature Difference and Evaluation Method

Analysis of substructure settlement and deformation should be carried out to confirm the compliance of the settlement and deformation after construction with design requirements before ballastless track is laid. The current method of settlement evaluation cannot meet the required frequency,accuracy and effectiveness due to the harsh natural conditions of the second double-track of Lanzhou-Xinjiang railway. To solve this problem,a multi-point static leveling settlement observation instrument is developed and representative construction site is selected to study the method for subgrade settlement deformation assessment. Research results show that(1) the laboratory test results demonstrate less than 1. 0 mm of absolute error of the instrument and the failure of field test to reach the accuracy of laboratory;(2) the index curve method and Asaoka method are successful to obtain better forecast result for the settlement observation of the second double-track of Lanzhou-Xinjiang railway under special climate condition;(3)Reducing the required curvilinear regression correlation coefficient from 0. 92 to 0. 85 is more applicable for the subgrade settlement evaluation of the second double-track of Lanzhou-Xinjiang railway.