Damage Evolution Analysis Of Rc Frames Structure Induced By Mining And Earthquakes

With the blasting technique widely used in engineering fields, the assessment of seismic effect and safety of structures becomes an important research topic in engineering.City tunnel construction site more concentrated in urban centers, along the surface buildings intensive. Therefore, to ensure the safety of buildings and tunnels the smooth construction of underground works.It is necessary to comprehensively study structural seismic structure effect and safety evaluation under the action of vibration.Therefore, under engineering background of Jiaozhou Bay of Qingdao blasting excavation of tunnel junction ,this article analyze the intensity of blasting vibration attenuation factors and propagation, structural dynamics theory of ordinary described with reference to the structural dynamics of blasting vibration theory, in summing up the general method of safety assessment based on the safety assessment system blasting vibration, and finally through the finite element software ANSYS , calculate and analyze dynamic response of engineering example of a frame structure under the action of the blasting vibration, vibration and seismic intensity Dynamic responses under comparison, in accordance with established safety assessment system blasting vibration safety assessment was carried out. This article on the structure under the action of the blasting vibration and the establishment of the dynamic response of the safety assessment system blasting vibration structure for building design and blast design and construction of the tunnel reference. The main research contents and results are as follows:(1) First,introduced the research background and significance; made research status and development review from three aspects of blasting vibration propagation and attenuation, blast vibration of the structure under the action of blasting vibration and structural safety assessment ,a system of safety assessment system is must be create in order for the safety of building structures to make a reasonable assessment.(2) Analyzed formation and the calculation of basic parameters of the blasting vibration and blasting seismic wave ,discussed blasting seismic wave propagation characteristics, including amplitude characteristics and spectral properties. Proposed the factors of blasting seismic wave intensity:including the explosive type of impact, blasting the number of segments of the effects of hole diameter, the impact initiation methods of blast vibration effects, the initial resistance line influence and communication media influence, and finally introduced in Qingdao Qingdao Jiaozhou Bay tunnel blasting vibration on-site client terminal case of the test ,gave the experience of the project Sa Randolph regression equation for the structural dynamic response analysis and security assessment prepared.(3) Based of dynamic analysis of the classical theory, studied the effect of blasting vibration dynamic analysis of the theory and method, described in detail blasting vibration response spectrum and time history analysis.(4) By comparative analysis of the effect of blasting vibration on the existing structural safety assessment, and presented its shortcomings, as established under blasting vibration safety evaluation system.(5) With the engineering example of a framework, the first in accordance with the "explosion safety regulations," preliminary analysis of the Criterion for the safety of the structure, and then build the structure of the software through the finite element model ANSYS, using response spectrum and time history analysis method dynamic analysis of structures, obtained the dynamic displacement and internal force response under the condition of the structure in the blasting vibration and shock conditions and earthquake intensity of to changes of similar, but the overall effect of blasting vibration the dynamic response of structures under earthquake intensity up than the shock value of the role of Under the much smaller, which, based on the response spectrum and time history analysis method to know the structure under the action of blasting vibration in the structural safety assessment.