Study On Seismic Damage Modes Of Masonry Building Structures

Due to its low cost and easily to get the materials, all the time, masonry structure is a major structure forms in towns and the framers'buildings in China. However, relative to other structure forms of architecture, architectural damage of masonry structure is particularly prominent in the devastating earthquake, especially in the earthquake on May 12, 2008 Wenchuan earthquake, that causes large numbers of casualties and heavy property losses. It is very necessary to do some thorough research work to improve the seismic capability of masonry building structures.Based on large amounts of literatures, summarize the damage features of masonry building structures in Wenchuan earthquake. By the method of comparing the numerical simulation results and actual damage, obtain some interesting results, Mainly lie in the following aspects:1. Firstly, this paper summarizes and analyses the development of history and current situation of masonry building structures. Analyse the seismic survey results of masonry building structures in Wenchuan earthquake, sum up the damage features of the masonry building structures in the earthquake, and preliminary analysis the reason of the destruction. Ulteriorly, summarize the problems in masonry building structures.2. Based on large amounts of literatures, summarize the domestic and foreign scholars'research achievements on masonry structure constitutive relation, the failure criterion and deformation modulus, and the calculation method about constitutive relation containing Single Passages only and deformation modulus selected from the research achievements apply to the calculation and analysis of the finite element model of masonry building structures.3. Using the nonlinear finite element analysis method, simulate the damage features of the dormitory of Xuankou middle school. Use ABAQUS software to establish the unitary finite element model of masonry building structures. Verify the feasibility to use the Damaged Concrete Plasticity material model to simulate the mechanical properties of masonry structure. Select the destructed masonry structure in Wenchuan earthquake as an example, a students'dormitory of Xuankou middle school on Yingxiu town in Wenchuan country, establish a simplified model of masonry structure, and choose the reasonable restraint elements to simulate the interactions between constructional column and wall. By the method of setting the tension and compression damage parameter to characterize structure damage, simulate the damage features commendably of the masonry building structures under the action of the earthquake: Typical"X"type shear inclined cracks on the pier; the pier containing constructional column destroys lighter, and the damage mainly appears in the joint of wall and constructional column; there is serious destruction on the breast and hollow horn; as a whole, structural damage present the rule that is asymptotic light from bottom to top structure, etc.4. Through the seismic damage simulation and the analysis of the nonlinear structure, discuss the effect of stiffness ratio of the pier to the breast for the damage modes of masonry building structures under the action of the earthquake: with the stiffness ratio of the pier to the breast increasing, the damage extent of the breast, as the vertical bearing component of masonry building structures, gradually ease, structural damage mode transforms that pier and breast are both are severely damaged to that the damage extent of the pier is obviously easier than the damage extent of the breast; with the stiffness ratio of the pier to the breast increasing, the phenomena that the time for pier of masonry building structures appearing severe damage lags behind the time for breast appearing severe damage is more obvious. The damage extent and the damage modes of the masonry structure are both similar, whose stiffness ratio of the pier to the breast is similar. Therefore, we can control the damage mode of the masonry structure by the way of controlling the stiffness ratio of the pier to the breast.5. This paper also adopt the Brittle cracking material model to simulate preliminary the collapse of masonry structure without constructional column.