Study On The Influence Of Structure Performance Of Earth-Sheltered Dwelling In Rainfall Infiltration

Earth-sheltered dwelling as a form of ancient buildings,which is China's distinctive form of folk house in loess areas.It take from nature,assimilated into nature,back to nature,with the construction of simple,warm in winter and cool in summer,saving energy,green environmental protection and a series of advantages.At present,there are still nearly 10 million people living in the cave of the Loess Plateau.Due to its unique structure and the characteristics of loess materials and other issues,earth-sheltered dwelling have multiple quality diseases,especially the frequent disrepair under the rainfall infiltration,serious threat to the lives and property of the residents.Rainfall has not only increased the density of soil,also reduce the strength of soil mass,which affect the stability of the cave.Therefore,To carry out the research of structural properties of earth-sheltered dwelling in Rainfall infiltration and disaster formation mechanism,has certain theory significance,also has enormous social and economic benefits.Thus,this paper based on the earth-sheltered dwelling of the western region as the research object,at the support of the nation “Twelve Five-Year” science and technology support projects(Issue number: 2015BAL03B03),analysis the the structure of properties of earth-sheltered dwelling in Rainfall infiltration,mainly doing the following work:(1)Select loess of western Henan,production of remodeling loess soil column to simulate the natural water content of the loess soil layer,Perform indoor rainfall simulation test,get the depth of infiltration under different rainfall and the distribution of water content in soil with different infiltration depth,the mathematical model of rainfall and infiltration depth and water content of infiltration soil was established,quantitative analysis of rainfall infiltration in loess.(2)Through the buried humidification test of the undisturbed soil samples,determined the density of loess with different moisture content,and carried out the elastic modulus tests and the triaxial shear test of remolded loess samples on 10 kindsof moisture content,the elastic modulus,cohesion and internal friction angle of loess with different moisture content were obtained,analyzed the influence law and mechanism of water content on the physical and mechanical properties of loess,established the loess density,elastic modulus,shear strength and moisture content of the mathematics model,provide a basis for parameter in numerical analysis.(3)Combined with field research and test results,select the appropriate research object,structural size and material parameters,using the numerical analysis method to establish covering thickness of 3 m's raw soil pit furnace numerical model,contrast analysis the displacement,stress and strain characteristics of raw cave in the rainfall infiltration depth of 1m,2m,3m.Finally got the structure weak parts of the structure under different rainfall infiltration depth and disaster formation conditions.(4)In order to further analysis thickness of covering soil effects on the stability of cave under rainfall infiltration,established the raw soil cave model of covering thickness of 2~5m,analyzed the displacement and strain characteristics of raw soil caves under the most rainfall infiltration depth of the the western region of Henan province for nearly 20 years,got the influence law of thickness of covering soil on the stability of cave under rainfall infiltration and the optimal soil thickness under this rainfall infiltration depth,the results show that the thickness of soil cover in the western part of Henan Province is mainly 3 ~ 4m scientific rationality.(5)Analyzed the stress mechanism of the raw soil cave without considering the infiltration of rainfall,based on the Protodyakonov's theory and since the support structure features of raw soil cave,kiln top natural balance arch height formula and vault collapse of critical depth formula is deduced,and combined with numerical simulation results verify the validity of the theoretical calculation,it provides a theoretical basis for analyzing the influence mechanism of rainfall infiltration on the structural performance of the raw soil cave.(6)Based on the analysis of the rule changes of the kiln top balance arch of the rainfall infiltration,the sensitivity of the balance arch height and the relative relationship between the rainfall infiltration depth and balance arch,expound elaborate the damage mechanism of soil under rainfall infiltration,Obtained calculation method of raw kiln in critical rainfall infiltration depth and optimal overburden thickness,andanalyzed the influence of rainfall infiltration on the raw soli cave's collapse,deduced critical collapse depth formulab of raw soil cave under the rainfall infiltration.