Experimental Study On Brick Masonry Farmhouse Influenced By The Mudslide Of Beijing

Debris flow is one of the widespread natural disasters in mountain areas, its characteristics are sudden and instantwith damages of impact, scouring and erosion, serious damages are made to the rural buildings, structures and the safety of residents and property, causing serious economic losses and casualties. Debris flow are determined by comprehensive factors of topography, geomorphology, geologic structure, hydrometeorology and human economic activities.Through the access of Beijing local Chronicles, statistics shows the information of debris flow disasters happened in history. According to the distribution of debris flow gully and its dangerous degree, the risk of debris flow in suburbs is divided into four levels based on the principle that the higher the risk, the higher the rank.The chosen of six districts included nearly 30 villages about building construction, structure, dimensions, size and position of windows, foundation types, ring beams and constructional columns, seismic reinforcing measures, heat insulation measures, relative position of the surrounding mountains and rivers, the ages and frequency of debris flow events, emergency measures is based on its risk ratings. This provides a practical basis for test and simulation analysis.According to the results of investigation, most of building structures in rural areas of Beijing are brickwork structures, whose types of masonry mortar are cement mortar and lime mortar. The experiment is composed of a group of compressive strength test to obtain the standard intensity value,10 groups of compressive strength tests for mortar specimens to get the variation rule between immersion time and its compressive strength,10 groups of shear strength tests for brickwork specimens to obtain the variation rule between immersion time and its shear strength, and 18 groups of compressive strength tests for brickwork specimens to get the variation rule between immersion time and its compressive strength.Finite element simulation analysis is based on investigation and test. Dynamic pressure, static pressure and turbulence velocity of building structures under different water velocity were calculated by FLUENT on the first step. Dynamic pressure was added on the ANSYS 3D model as triangular surface load, considering the dynamic effect of debris flow, to get stress and displacement distribution.By comparing the experimental result with the FEA calculation, conclusion was made. If FEA calculation is larger than experimental result, it means that the houses are severely damaged and have no need to be strengthened. Otherwise, building constructions can be consolidated to recover its normal usage function. According to the damages of buildings, the reinforcement measures are put forward to provide theoretical basis for reinforcing the building constructions in mountainous areas of Beijing.