The Research Of Land Subsidence's Master-control Factor Created By Men

Land subsidence, as a kind of geological disaster in environment, has already affected living environment of mankind seriously, and caused tremendous economic losses. The study of land subsidence's master-control factors created by people, will contribute to understand deeply the genetic mechanism of land subsidence and establish rationally mathematic model of land subsidence, further provide theoretical guide and scientific basis for defining man-made master-control index of land subsidence .On the basis of a new understanding that land subsidence is caused by mining ground-water and increasing load on the earth's surface altogether, the paper 'discussion centre on mechanism of land subsidence caused by the two master-control factor by people. By case study in land subsidence for mining ground-water, we find: critical water-level may be considered as master-index of controlling land subsidence and developing or using groundwater resources in maximum limit, and the way of defining critical water-level provided by the initial groundwater drawdown is relatively simple and precise. To land subsidence caused by increasing load on the earth's surface, this paper probes and researches the land subsidence caused by load foremost by indoor model test, and under Jacob assumptions, reduces the mechanism expression of land subsidence caused by load, the results show: Load may cause land subsidence certainly, simultaneously may go up water-level of aquifer; Under load, there is marked linear correlation between land subsidence and ground water-lever, and the coefficient of linear correlated function is aquifer's elastic skeleton storage coefficient; According to above mechanism expression and indoor model test, we may estimate and calculate the land subsidence caused by creasing load on the ground surface.