Study On The Key Techniques For Stabilizing Ancient Landslides Of Expressway

Ancient landslide disaster of expressways is the unavoidable engineering problem when expressways'construction extends to mountainous areas in the past decades.The main characteristics of ancient landslide disaster are:large scale, calamitous, long and costly damage-control period, and inducing nature can't be known in a short time, all of these require technicians and research scholars adhere to the geology-based principle during the choice of expressways'routes.If ancient landslide disaster could be confirmed in the prophase, dodging principle should be taken superiorly, while when ancient landslide disaster could not be avoided or confirmed and resurges during the construction, active and effective engineering measures must take.Through valid prospecting and based on its transformation characteristics and failure mechanism, treating directly at the disaster, eradication without any future trouble left could be approached.According the ample treating cases of ancient landslide disasters in mountainous areas' expressway of Fujian province this paper first summarizes the characters and types of ancient landslide disasters in mountainous areas'expressway of Fujian province, from the qualitative point, engineering countermeasures for each kind of ancient landslide disaster are brought forth; then the requirement of prospecting details and techniques for each phase during the construction of expressways are put forward; for the common application of anti-slide pile in ancient landslide disaster, an immature opinion about post-construction evaluating method is brought forward at last.The main contents and innovation of this paper are as following:1. The failure characteristics and failure mechanism of ancient landslide disaster in mountainous areas'expressway of Fujian province are listed and classified clearly, at the same time, from the qualitative point, relative countermeasures are recommended.2. One of the most important factors, the action and influence of slope excavation, which induces the resurgence of ancient landslide disaster during the construction of expressway is stressed, mechanical mechanism and effect due to slope excavation is discussed also, then the different resurging nature and extent of ancient landslide disaster result from expressways cross different sections of slopes are advanced..3.Details and essence of prospecting techniques of ancient landslide disaster are comprehensively narrated in this paper, in order to corresponding with the four phases during the construction of expressway, four phases including prophase feasibility study, prospecting and designing phase, construction phase and maintenance phase, for the prospecting of ancient landslide disaster are suggested; meanwhile, comprehensive instructing contents including prospecting focal points, prospecting methods and the requirement of prospecting techniques for each phase are proposed as well.4. Four post-construction evaluating methods, that is, numerical analysis method, model experiment method, onsite test method and all-round analysis method, of anti-slide pile engineering are suggested in this paper. A new thought are brought forth in the on-site test method, that is, the transformation development of ancient landslide disaster during the maintenance of expressway, measuring inclination hole inside molded anti-slide pile should penetrate the bottom of anti-slide pile 8-10 meters or even longer bedded rock(based on geological conditions),Combing the deep displacement monitoring and anti-slide pile displacement monitoring, so post-construction evaluation of anti-slide pile engineering could be relied on these firsthand data.