Papers by Keyword: Land Subsidence

Abstract: Land subsidence is one of the major environmental geological problems in the construction of Daxing new town. In this paper, the characteristics, formation conditions and influence factors of land subsidence in Daxing new town were described. Using Modflow software, land subsidence calculation model was established, and the land subsidence trends were predicted, which provides basis for the construction, planning and land subsidence control of the new town.

Abstract: In recent years, with the establishment and perfection of legal system, the building of the legal system has attained considerable achievements, but the actual operational results of law enforcement show out ineffective, various related disputes resolution mechanism needs to be established and perfected. Disputes between the state-owned coal enterprises and farmers are interests disputes between specific bodies, as there are typical performance and character in the litigation resolution mechanism of disputes between the state-owned coal enterprises and farmers, therefore its necessary to analyze and elaborates the motivators, operation mechanism and outcomes consideration of litigation which is contained in the process of litigation resolution.

Abstract: In recent years, with the gradual establishment of the socialist legal system in China, the construction of legal system is tending toward perfection. But the actual operating effects of law enforcement are relatively not ideal. Social group disputes occurred frequently. In this paper, three typical litigation disputes between the state-owned coal enterprises and farmers caused by coal mining are taken as examples to elaborate the concrete practice process of the law in the litigation disputes. In order to explain the inner logic of legal practice in specific disputes, the external conditions, the internal mechanism and deep motivation in the disputes which influenced the legal practice process are analyzed. Finally its concluded that the consideration of legal effect and political power operation determines legal judgments in these litigation disputes, furthermore, explains legal practice process in specific disputes.

Abstract: Due to long-term excessive exploitation of groundwater, serious land subsidence has been caused in Cangzhou City, Hebei Province, China. With GIS spatial analysis method, this paper conducted an analysis of the quantitative relationship between deep groundwater exploitation and the land subsidence in this area. This quantitative relation was analyzed by using data of both long-term and short-term time series. The long-term time series analysis indicates that the land subsidence volume accounts for 57.6% of the amount of deep groundwater exploitation, indirectly showing the proportion of released water from compressibility of the aquifers and the aquitards in deep groundwater exploitation. Some factors such as hysteresis effects of subsidence may be ignored in the short-term time series analysis, thus the calculated ratio becomes significantly large. From perspective of water resources evaluation, the long-term time series analysis is better to analyze the relation between land subsidence and deep groundwater exploitation.

Abstract: The governing equation was formulated for one-dimensional consolidation of the soil layer induced by time-dependent groundwater drawdown. Using Duhamel's theorem and method of separation of variables, analytical solutions were developed for the problem. Based on the solutions, the consolidation behaviors of the soil layer were studied and the factors influencing the consolidation were investigated. The results show that it is necessary to consider both the changes of total stress and pore water pressure on the boundary. The greater initial time factor T_vc is, the slower the rate of the consolidation is.

Abstract: Based on the characteristics of frequent land subsidence events caused by groundwater level fluctuation in coastal cities in China and studying on the quaternary sedimentary soft clay in Shanghai, the effects of groundwater level fluctuation on the deformation of soft clay is simulated by Geo-Studio finite element software. It has summarized the law of deformation, effective stress with the change of groundwater level fluctuation, especially the process of dissipation of pore water pressure with the groundwater level fluctuation. The low can be sued as a reference for similar engineering and land subsidence prevention.

Abstract: In study of a series of damages to water distribution systems caused by urban land subsidence, risk assessment modeling is necessary for risk management especially in Mega-cities. First of all, the Catastrophe Theory was employed to analyze the Catastrophe mechanism, and a function catastrophe simulation model was established accordingly to get the vulnerability index of water distribution system. Secondly, risk entropy model was used to analyze the risk of pipe network suffering the land subsidence with the disorder and uncertainty features according to risk theory. Finally, to get the risk index the water distribution system of Guangzhou city was taken to the risk assessment model utilizing the level of land subsidence identified by the dimensional analytical method. The results showed that the risk of land subsidence under the city water distribution system security upgrade is feasible to provide a risk assessment of the strategic decision-making model.

Abstract: Foundation Pit Dewatering always arouses surrounding land subsidence that has significant influence on the neighboring environment and even leads to serious natural disasters. So an accurate prediction of the settlement is the precondition of forecasting and evaluating the Foundation Pit Dewatering environment influence. Using the distance from settlement points to Foundation Pit, Equivalent compression modulus, the drawdown, Supporting structure stiffness and equivalent permeability coefficient as the independent variables, adopting the 38 groups of Engineering practical monitoring datas as the samples to establish the prediction model of Land Subsidence caused by Foundation Pit Dewatering based on Support Vector Machine theory. The project trial result shows that compared with traditional empirical method, the model possesses bigger forecast precision.

Abstract: The Hangu research area is belonged to the typical inshore soft soil area. The engineering geological properties of soil in the research area is rather poor. With the rapid development of Tianjin and the improvement of people’s living standards, with the increasing demand of people’s lives of with water and industrial water, a lot of groundwater exploited caused groundwater elevation changes and resulted in pore water pressure changes and leaded to effective stress changes of soil, which eventually caused land subsidence . Numerical analysis method is used to this paper to research land subsidence of Hangu,Tianjin.

Abstract: With the construction of deep and large foundation pit, land subsidence disasters caused by dewatering in deep foundation pit become very serious. Using the coupled model of foundation pit dewatering and land subsidence and putting it into foundation pit dewatering construction, analyzes and summarizes the effect of land subsidence in space and time, which will provide references for the design and construction of foundation pit dewatering.