高速铁路列车振动作用下黄土潜蚀机理研究

The erosion of the loess induced by the vibration of the train along the high - speed railway has a unique mechanism.Loess has a special loose porous structure and poor mechanical strength.Train vibration on the one hand formed the crack and destroyed the original structure of the loess, on the other hand also make the permeability of water in the loess enhanced Which exacerbated the development of the erosion.The application is intended to analyze the typical latent erosion development area along the high-speed railway, taking full account of the influence of the weakening of loess structure and the infiltration ability of water under the action of vibration. Through the ways of engineering geological surveying, power sensor monitoring, triaxial penetration test,loess microstructure analysis before and after vibration,quantitative statistics of crack to have the study on the effect of vibrating, shaking, expanding and infiltration of loess body and to explore the influence of combined action of vibration and water on the erosion of loess. on the basis of this, according to the theory of soil dynamics, plastic mechanics and variational principle to analyze the development process and formation mechanism of loess erosion which will give a new understanding caused by latent erosion to provide new theoretical basis for the high - speed railway construction.The research will have a good value on promote the sustainable development of local economy and promotion.

高速铁路沿线列车振动作用诱发的黄土潜蚀具有独特的形成机理。黄土具有特殊的疏松多孔结构，力学强度差，列车振动一方面形成的孔隙开裂、阔张，破坏了黄土原有结构，另一方面也使黄土中水的渗透能力增强，加剧了潜蚀的发育程度。本申请拟以高铁沿线典型潜蚀发育区为剖析对象，充分考虑振动作用下黄土结构破坏及水的渗透能力增强对潜蚀发育的影响。通过工程地质测绘、动力传感器监测、室内三轴渗透实验，振动前后黄土微结构变化分析、裂缝定量统计等方法来研究黄土体的振松、振裂、阔张效应及渗透能力改变效应，探讨高速列车振动与水联合作用对黄土潜蚀的影响。在此基础上，按照土动力学、塑性力学和变分等相关原理定性定量分析黄土潜蚀坑、穴的发育过程及形成机理，对此类由列车振动引发的黄土潜蚀机理有一全新的认识，并为其防治提供新的理论依据。研究对加快黄土地区高速铁路建设，推动地方经济的可持续发展具有十分深远的意义，具有广泛的应用推广价值。

通过项目研究，以高铁沿线典型潜蚀发育区为剖析对象，高速铁路沿线列车振动作用诱发的黄土潜蚀具有独特的形成机理。黄土具有特殊的疏松多孔结构，力学强度差，列车振动一方面形成的孔隙开裂、阔张，破坏了黄土原有结构，另一方面也使黄土中水的渗透能力增强，加剧了潜蚀的发育程度。项目研究充分考虑振动作用下黄土结构破坏及水的渗透能力增强对潜蚀发育的影响。通过工程地质测绘、动力传感器监测、室内三轴渗透实验，振动前后黄土微结构变化分析、裂缝定量统计等方法来研究黄土体的振松、振裂、阔张效应及渗透能力改变效应，探讨高速列车振动与水联合作用对黄土潜蚀的影响。在此基础上，通过项目研究，按照土动力学、塑性力学和变分等相关原理定性定量分析黄土潜蚀坑、穴的发育过程及形成过程，得出了高速铁路黄土路基潜蚀灾害发生发展的一般规律及黄土潜蚀的机理，即在水的作用下黄土渗透性及结构发生改变，进而引起的连贯性塌陷。对此类由列车振动引发的黄土潜蚀机理有了一个全新的认识。项目研究分析了影响潜蚀发育程度的黄土湿陷、土层张力、土层含水量、土层压力等因素，并阐明了其之间的相互关系。在此基础上提出了高铁黄土路基防治潜蚀灾害的参数建议，即当路基土层含水量达到（或超过）25%左右，潜蚀现象（塌陷、陷落）极易发生，对应的最优路基防渗处理范围，应在路基地层渗透性改变范围的1倍到1.5倍距离。项目研究成果对加快黄土地区高速铁路建设，推动地方经济的可持续发展具有一定的意义，具有广泛的应用推广价值。