Loess Areas The City To Crack The Disaster Research

Study on the microcosmic and macroscopic structure of the loess has shown that the characteristics of the loess provided a condition for the creation of the ground fracture. The special tiny view structure of the loess makes the loess own a lot of characteristics, lower plastic, collapsibility, higher permeate, macropore and higher strengtn etc. Thus, these characteristics cause the loess geologic strata to take place frailty to break easily, to collapse by moistening, to often appear structural joins, and to own higher unconfined compression strength to maintain deeply long crack to exist. The phenomenon of the ground fracture appears in the loess geologic strata easily under the erosion of the water.Xi'an is a typical loess region city. Xi'an ground fracture is a typical the earth fractures hazard. In the earth's surface loess layer, developing mechanism of the ground fracture of Xi'an have four kinds of modes: tectonic movement mode, extraction of groundwater mode, the load brought by the additional stress of city and the earth's surface water to permeate mode.To study the earth's surface water to permeate mode, the infiltration test in situ is located on one of Xi'an ground fractures(f₁₂), where plenty of testing data is collected by continuous observation. According to analyse testing data, it is shown that a landing funnel is located on the test pit. An analysis based on the logarithms coordinate system has shown that the preinfiltration capacity(Q_b) is 28m³. Then, according to experiment the place parameter, pass finite element analysis(FEA), discover model in response to the dint and meet an emergency development trend and measure a data actually basic fit together.