The Stress And Deformation Analysis Of The Entrance Door In The Underground Cave Dwelling

The underground cave dwelling is a unique architectural style in the loess plateau region of China.It’s considered to be a precious cultural heritage with greatful wisdom and diligence of natives.The underground cave dwelling has many ecological characteristics that it is warm in winter and cool in summer and has good heat insulation performances.So,it is thought to be a true “green building”.A ramp structure called entrance door is built due to the altitude of cave dwelling,which causes a underground village landscape that people on the ground can not find the natives lived in the cave dwelling at once.The entrance door is playing an important role in cave dwelling because it is the only hub connecting kiln yard and the ground.The structure characteristics of the entrance door will directly affect people in and out of cave dwelling and affect residents’ life and property safety.However,the study about the entrance door with changeable space,complex stress and unique structure style is still in the blank so far.In view of the existing situation,this paper studies the stress and deformation law on the entrance door,and discusses how different factors influence the stress and deformation on the entrance door.This paper based on the "Twelve Five-Year" national science and technology support program project-"Study on Key Technology of Safety Improvement of Traditional Cave Dwelling Building Structure"(Issue number: 2014BAL06B03),with the entrance door of cave dwelling as the research object,mainly carried out the following work:(1)This paper focus on the main forms of the entrance door,Feng shui layout,the main parts and structural characteristics,common quality diseases and construction process of the entrance door through practical investigation in western Henan Province.(2)This paper obtains the basic sizes of cave dwelling structure calculation model via statistical analysis on lots of test research data,and gets density,elasticmodulus,cohesive stress and inner friction angel of local loess by doing experiment on physical and mechanical properties of loess.We use a finite element analysis soft to establish the finite element model of whole cave dwelling structure and calculate and analysis the regularities of the stress and deformation to seek out the weakpositions of entrance door.(3)In order to analyse the stress and deformation effects of overlying soil thickness of the transition space on dome structure,established the entrance door models of covering thickness of 1m,1.5m,2m,2.5m,calculated and contrastively analysed the stress and deformation of dome structure,quantitatively analysed the influence law of stress and deformation of overlying soil thickness on dome structure,finally it is concluded that the overlying soil thickness of 2m~3m is a better choice.(4)In order to analyse the stress and deformation effects of overlying soil thickness of the junction between opencut tunnel and underground tunnel on underground tunnel structure,established the entrance door models of covering thickness of 0.5m,1m,1.5m,2m,calculated and contrastively analysed the stress and deformation of underground tunnel,quantitatively analysed the influence law of stress and deformation of overlying soil thickness on underground tunnel,finally it is concluded that the overlying soil thickness should be greater than 1m,less than2 m.(5)In order to analyse the stress and deformation effects of intersecting angle of the two tunnel cylinder on the entrance door,established the entrance door model of intersecting angle of 60°,90° and 120° based on study variable of intersecting angle,calculated and contrastively analysed the influence law of the stress and displacement of different intersection angles on the entrance door,finally it is concluded that the most appropriate intersection angle of the entrance door is 90°.(6)In order to analyse the stress and deformation effects of expansion space on entrance door,established three expansion spaces with same size in different locations near the transition space of entrance door,calculated and contrastively analysed the influence law of displacement and stress on the entrance doorway when three expansion spaces exist separately or simultaneously.