| The serious ground deformation could cause serious geological hazards regionally,such as land subsidence,ground fissures,ground subsidence and so on,which are directly threatening the safety and stability of buildings and urban lifeline system engineering.Aiming at the analyzing the identification control factors and cause mechanism of the evolution of ground deformation in North China Plain,which is influenced by multiple factors,this thesis conduct the study of analyzing evolution characteristics and influence factor,using the methods of structured storage of multi-field information,geostatistical analysis,numerical simulation and comprehensive evaluation of multi-field coupling and multi-objective optimization,based on the theory of volume equation relations and multi-field coupling between land deformation and multiple factors,as well as geological hazard risk assessment.The study methods and results could provide reference for risk identification and mitigation controlling measures formulation of regional deformation hazards,and the optimization of engineering facilities and disaster prevention planning.In order to identify and analyze the control factors during the different evolution stage,this thesis builds the multiple information database of deformation-related factors and background information in North China Plain,conducts quantitative description of characteristics for the determined stages.Furthermore,multi-field coupling numerical simulation models are founded for both regional and local area to analyze the different impact and coupling effects accordingly to study process mechanism.On this basis,the model of risk assessment of ground deformation hazards is established which is improved by TOPSIS-AHP theory,and the relatively safe risk evaluation and controlling regionalization results are obtained to put forward targeted preventation measures including optimized monitoring facilities by multi-objective optimization model.(1)Current research status of monitoring methods,analysis methods and theories of evolution process,mechanism and disaster risk assessment of ground deformation are reviewed in this paper.This paper discussed the existing problems and key research directions for ground deformation in the field of geo-environmental engineering.It summarizes the characteristics of major means of ground deformation monitoring and the main results obtained in North China Plain,and discusses the effectiveness,solutions and basic index frame for quantitative analysis of evolution characteristics and causation.The subjective index weighting problem and trend of the research are put forward based the reviewing of hazards assessment model and method related to ground deformation.(2)Based on the integration multi-source background spatial data covering the fields of deformation,tectonic geology and hydrogeology and human activity,the regional multi-source information and effect analysis database is constructed,which provides the data support the quantitative analysis of evolution characteristics and maincontrol factors by geostatistical methods.There are 40 quantifiable indexes and 113.8million records of multi-source information integrated by structural data storage method to build the multi-source information and effect analysis database for North China Plain.According to database,the study of evolution characteristics,and the volume relationship between groundwater exploitation and deformation are concluded to identify the major factors and verified by the preliminarily comparative analysis based on the PS-In SAR inversion results in typical deformation areas.(3)Combing the theory of multi-field coupling numerical simulation,this thesis constructed the Tectonic-Seepage numerical model for both regional and typical deformation area to analyze the influence of multi-factor coupling effects for deformation according to 30 simulation scenarios,and complete the evaluation of the sensitivity varieties and impact effects of different influencing factors.The results showed the significant consistency between the ground deformation and influence factors including tectonic amplitude and the depth and variation of groundwater level,the weak correlation of other factors that covering smaller tectonic impact depth and angle,as well as the higher compression ratio and thickness of Quaternary Strata.Meanwhile,the coupling effect of groundwater exploitation and tectonic displays the lower displacement than the sum deformation caused by single factor.Furtherly the results calculated by the non-parametric rank correlation and improved principal component analysis exhibits the mainly controll effect of groundwater exploitation which shows high correlation coefficient of-0.6661and-0.8321 with the depth and variation of deep groundwater.(4)In this paper,the risk assessment index system of ground deformation disaster is constructed,the risk assessment is conducted by improved methods combining AHP method and TOPSIS theory,and the management and control zoning research is completed regional considering the distribution of linear engineering facilities and the requirement of city planning.Based on the disaster risk assessment index sets covering hazard-formative environment and factors,as well as the exposure and the preventionmitigation level for hazard-affected bodies,are combined with the weights calculated by AHP method,adopting the constructed TOPSIS optimization model to obtain the relative safe risk evaluation value and zoning result of deformation hazards considering the distribution of regional linear projects,the city-regionalism and the impact of regional water transfer system.(5)Combined with the influence of regional operation stability and suitability of monitoring network stations and monitoring quality,the stability for station is calculated combined of improved principal component analysis result as well as the synthesized effect of terrain,water,vegetation,traffic and other factors,Then the suitability is obtained considering the distribution of liner project,the existing monitoring station and the risk zoning result by multi-objective optimization.The optimization results showed maximum interpolation error reduction of 43.4%,the well covering for high monitoring demands areas and the correspondingly higher average values 0.6938 for stability and0.5379 for suitability.The quantitative evolution characteristics and comprehensive effect of deformation influence factors relying on the regional multi-source information and effect analysis database,and reconstructed multi-field coupling numerical simulation process and recognizing mechanism of evolution development is proved to be reasonable and effective.Furthermore,the study methods and results could provide theoretical and practical significance for the identification analysis of the main controlling factors of the temporal-spatial evolution of ground deformation,and the assessment,prevention and control measures of disaster risk for regional linear engineering deformation,and could provide useful reference for the quality evaluation and optimization analysis of deformation monitoring network. |
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