Research On Typical Damage Characteristics And Reinforcement Technology Of Loess Cave Dwellings In Shanxi Province

Premier Li Keqiang of the State Council pointed out that the goal of building a moderately prosperous society in an all-round way will be benchmarked,and the poverty alleviation and rural revitalization will be solidly promoted in the 2019 government work report.Insist on giving priority to the development of agriculture and rural areas,strengthen the overall coordination of poverty alleviation and rural revitalization,and ensure that the goal of poverty alleviation is achieved on schedule and that farmers’ lives reach a comprehensive level of welloff.The most difficult task for building a well-off society in an all-round way is poverty alleviation.The most prominent shortcoming lies in the rural poor.Among them,solving the problem of rural housing security is an important task for poverty alleviation.The loess cave dwelling is a unique form of adobe building on the Loess Plateau in my country.It has a long history and is warm in winter and cool in summer.It is suitable for living.It is still one of the main architectural forms of rural residential houses on the Loess Plateau.Because loess cave dwellings are generally built with a long history,and they have been subjected to repeated effects of weathering erosion,water seepage,dampness and drying on the roof for a long time,and the long-term effects of plant roots,loess joints,freezing and thawing,etc.loess cave dwellings often appear cracks,water seepage,etc.Various forms of diseases such as roof fall and slumping can even cause "kiln destruction and death" in severe cases.The safety and repair protection of loess cave dwellings are the top priority to solve the housing safety problem.The loess cave dwellings in Shanxi Province are widely distributed,and have a long history,have fallen into disrepair over the years,and the disease problems are more prominent.According to the distribution and destruction status of loess cave dwellings in Shanxi Province,this paper summarizes the types of loess cave dwellings in Shanxi Province through the method of consulting data and field investigation,and analyzes the distribution characteristics of loess cave dwellings in Shanxi Province and the typical destruction types of loess cave dwellings;This paper analyzed the physical and mechanical properties of loess in different cave dwelling areas in Shanxi Province through the indoor experiment on loess in different areas of Shanxi Province;taking cliff cave dwellings as the research object,single-hole cave dwellings against cliffs and double-hole cave dwellings against cliffs were selected.The ABAQUS numerical simulation software was used to analyze the physical and mechanical properties of loess.Numerical simulation analysis was carried out,the force and deformation characteristics of loess cave dwellings were studied,and the failure mechanism of loess cave dwellings was analyzed.Finally,through the summary of the investigation and the analysis of the numerical simulation results,specific suggestions and methods for the reinforcement of the loess cave dwellings are put forward.The main conclusions drawn are as follows:First,taking the geological characteristics,climatic characteristics and humanity history of Shanxi Province as basis,this article divides the distribution areas of the cave dwellings in Shanxi Province into five categories,namely cave dwellings in the west of Shanxi,cave dwellings in the north of Shanxi,cave dwellings in the middle of Jin,cave dwellings in the south of Shanxi,and cave dwellings in the south of Shanxi Province..Based on the topography,cave dwelling construction methods and construction methods,the common types of cave dwellings in Shanxi Province are mainly divided into the following three types: cliff dwellings,sunken cave dwellings and independent cave dwellings.Second,through field investigation,the types of loess cave dwellings in Shanxi Province were summarized into five categories: kiln face spalling and kiln body cracks,water seepage,roof fall,and slumping.The cracks in the kiln body can be divided into horizontal cracks,longitudinal cracks and cross cracks under the action of large external stress;the cave roof fall can be divided into kiln face roof fall and arch ring roof fall according to the location of the roof fall and the severity of the roof fall;According to the scope and extent of the landslide,it can be divided into local landslide and overall landslide.Factors affecting the destruction of loess cave dwellings mainly include irresistible climate,geological factors,loess joint development,seepage from external water sources,destruction of animals such as wormholes and rat holes,the role of plant roots,etc.As well as thin covering soil and insufficient width of kiln legs,Structural problems such as the imbalance of the kiln arch ratio.Third,the single-hole and double-hole cliff cave dwelling models were established through the ABAQUS software for numerical simulation.The numerical simulation results showed that the stress and displacement of the single-hole cliff cave dwellings are very symmetrical,and the stress and displacement changes at the selected measuring points are almost It is completely symmetrical about the central axis of the kiln face.The largest deformation and the weakest place lies in the vault of the cave dwelling.Therefore,when the cave dwelling is reinforced,the vault should be strengthened more firmly and reliably;the two holes in the cave dwellings are supported by the cliff.The stress and displacement changes of the cave dwellings are basically symmetrical with respect to the kiln legs.The cave dwelling vaults and kiln legs have greater stress and deformation,and deformation and cracking are most likely to occur,leading to the destruction of the cave dwellings.Fourth,the kiln face is prone to local fragmentation and collapse under the effects of rain erosion and weathering for a long time.When the kiln face is severely eroded and weathered or partially collapsed,brick（stone）masonry and anchor rod reinforcement mesh-sprayed concrete can be used.Reinforcement method: The diseases of the cave-dwelling kiln body include cracks,water seepage,roof fall,etc.It is recommended to use the filling and plastering method,the internal support method and the lining method for the reinforcement of the kiln body,and the reinforcement design drawing and corresponding technical parameters are given.This paper investigates and studies the status quo of loess cave dwellings in Shanxi Province,which has important theoretical and practical significance for protecting and developing cave dwellings,ensuring housing safety,winning the battle against poverty,and realizing a well-off society in an all-round way.