Development of surface movement experimental platform and experimental study of buildings in mining area

The mining influence of village buildings in the coal mining area is related to the local people’s livelihood and social stability. It is necessary to study the influence law and protection measures of surface movement and deformation on building damage and protective measures. However, there is still a lack of effective physical simulation methods for quantitative experimental research on house damage in mining villages. Therefore, this paper proposes a design concept for the surface movement experimental platform based on the time-sequential loading of supporting columns and the quantitative calculation of three-dimensional movement, develops the surface movement experimental platform with multi-point support and three-dimensional loading control. The multi-scale geometric and mechanical similarity theory of “brick (point)- masonry wall (surface)- building (body)” for the house model is established, and the production process of village building model based on similarity theory is studied. Taking the A village building in Fengfeng mining area as an example, the simulation experiment is carried out. The models of large-span building with bottom beams, large-span building without bottom beams and small-span natural building are made, and the damage characteristics of three types of buildings under different movement and deformation are quantitatively analyzed. The experimental results show that the gypsum powder and water at 7∶1 mixed as aggregate, alcohol adhesive as binder, can be used as the optimal simulation material and parameter ratio of the building; under the same magnitude of surface deformation loading conditions, small-span and bottom beam building has good ability to resist surface deformation. the damage degree of the building under the combined deformation is greater than that of the single deformation. Affected by the horizontal tensile deformation, the wall surface has an eight-shaped oblique crack, and the horizontal crack at the connection between the roof and the wall; when the positive curvature of the ground surface is deformed, cracks appear on the top of the wall, roof and window corners of the building, and the cracks on the roof and door corners are easy to connect. It is revealed that there is a linear positive correlation between the crack width of the roof and the positive curvature deformation of the surface, and there is an “S” type positive correlation between the crack width of the door and window wall and the tensile deformation of the surface. By comparing with the field measurement, the shape and location of the cracks in the building are basically consistent with the model experiment results, which verifies the reliability of the simulation experiment platform. The development of the automatic control surface movement mechanization simulation experiment platform, the production of the building model and the experimental research results of deformation damage can provide a new research method for physical simulation and damage evaluation of buildings (structures) in mining area, and provide a reference for the study of the building damage mechanism and the reinforcement and maintenance.