青藏铁路冻土区路基工程安全可靠性监测技术研究

通过对冻土区路基工程和冻土之间相互作用过程的分析,提出冻土区路基工程的安全可靠性监测关键技术一是监测方法,二是监测手段,三是数据分析。冻土区路基工程的安全可靠性首先取决于工程周围和工程基底多年冻土的热稳定性,其次取决于发生变形的路基填土厚度及其基底融化层厚度。因此,路基顶面以下不同深度地温监测和年际冻融季节时段路基土层变形监测是冻土区工程长期可靠性监测的主要指标。青藏铁路自然条件的严酷性,要求监测手段具有可靠性和耐久性以及对复杂自然条件变化的适应性。文章提出一种自动观测多年冻土地温和路基变形,并能够实现数据无线传输的现场监测系统设计方案,通过现场试验,证明这种监测系统能够适应青藏高原恶劣的自然条件,减轻了人工监测的劳苦,具有可靠性和耐久性。作者还提出了能够简便判断冻土区工程安全可靠性的监测数据分析方法,对目前冻土区工程安全可靠性分析具有一定的理论指导作用。

MONITORING TECHNIQUES FOR CONSTRUCTION SAFETY RELIABILITY OF PERMAFROST SUBGRADE FOR QINGHAI-TIBET RAILWAY

In this paper,the key techniques of safety reliability monitoring in subgrade construction in permafrost are provided according to the analysis of the interaction process between subgrade construction and the permafrost.The key techniques have the techniques,motoring methods and data analysis methods.The safety reliability of permafrost subgrade construction depends on the thermal stability of the permafrost around and at the bottom of the construction and the thickness of deformed road-base fill and the beneath thawed layer. Therefore,the soil temperatures at different depths under the railway base surface and the deformation of railway base fill during the annual freezing and thawing periods are the main indexes in the long-term reliability monitoring of road-base construction in the permafrost.The extreme bed natural conditions demand that the means of monitoring must be reliable,durable and flexible.This paper discusses one set of monitoring system It has been verified with field test.Besides,the paper presents a method for analyzing monitored data for enhancing the judgment of the permafrost construction reliability.