Study On Surveying And Monitoring Technology Of Loess Landslip

This thesis has studied two practical techniques on exploring and controlling of the loess landslip: First, aiming for the problem of the difficulty to identify the sliding zone, we have developed a set of drilling tool suitable for loess landslip; through observing and testing, we have seek after the characteristic signs of how to discern loess slip zone. Second, we have developed a long-range wireless datum transmission system suitable for monitoring of landslip.Loess is of such characters as low moisture content, high intensity, apparent structure feature, but meeting water, the intensity is reduced rapidly, and the structure is apt to be destructed etc, landslip drilling requires full sample explored consecutively in whole hole without disturbing. And the technological key of designing bit is to adopt dual pipe and the outer writhing with properly big calibre. Two kinds of specifications (146mm and 219mm) drilling tool has been developed in this research, their liquid would be circulating in the apeture of the inner and the outer pipe, thus to slow down water to imbrue soil, and the inner, without rotating, could play a protective role on soil core. Through in-situ drilling test, if drilling adopts mud as circulating liquid, it can make a good result, the result of the 219mm calibre drilling is better. It is unsuitable to adopt drilling by dry way or use immaculate water as circulating liquid.We, taking 4 typical loess landslides located in Jingyang County along Jing river, named Dong feng landslip,Shu tangwang landslip, Xiu chidu landslip and Tai ping landslip etc.to study, through in-situ revealing and measurement and sampling test, wanted to identify signs of the sliding zone. The result of study shows: the slide area soil's physical property difference, the electric resistivity variation, and the exiguous structure characteristic are obvious, could be the marks of slip zone, while the mineral ingredient, the micro structure characteristic and the chemical composition of the sliding zone are not remarkable, couldn't generally be the marks of the slip zone.This thesis has also developed a set of long-range wireless datum transmission system for landslip monitoring, which is made up of three major parts: control center, GSM network and leading terminal station. One of the system's ends joins the monitoring instrument fixed on the monitoring point in landslip, the other end links with control center. The one-chip computer controls and gathers and changes with A/D the parameter from sensor of the leading terminal station, the receiving and dispatching module (TC35) conveys the data to the control center by GSM after dealing with, in order to realize the tasks of data transmission, data management, establishment of monitoring model, dispatching of prewarning message; besides it could analyze and process the monitoring data, for researchers to use. This system offers the advanced technological means for predicting and monitoring landslip accurately, being of advantages of real-time, inexpensive cost, flexible organization of network, unlimited circumstance, convenient centralized management, and stability performance etc.