Research On The Aseismic Behavior Of Spandrel

Item 7.2.2 and 7.2.3 in the present domestic Architectural Code of Anti-seismic Design only mention the checking computation methods for anti-quake of pier between windows, fail to mention the computation process for spandrel. Therefore, all kinds of designing institutes and colleges have not been able to put forward the specific computation of spandrel. However, both the seismic hazard survey and photographs in Tangshan Earthquake reflect that the damage in spandrel is not at all inferior to that of the pier between the windows. The seismic hazard report of Baotou Earthquake also mentioned the damage of spandrel in multi-story brick houses. And it was mentioned once more in the seismic hazard report of the recent Dayao-county Earthquake in the Yi Nationality Autonomous Prefecture in Chuxiong, Yunnan Province. Objective facts are the starting points of scientific research. Why this problem has not caught our attention is mainly due to that we are accustomed to handle stress analysis by means of mechanics of materials. So we assume that the shear stress of spandrel is much less than that of pier between windows, and we fail to take into account the cracking phenomena in spandrels when making aseismic strengthening to dilapidated buildings.Using the analytical method of applied mechanics of elasticity, this paper, theoretically, makes specific analysis and computation of the shear stress in the spandrel, pier between the windows and adjacent walls, and obtains the horizontal shear proportion 1:1.1052 between mid-points of pier between windows and spandrel. Electro-experiments prove that the horizontal shear proportion between mid-points of pier between windows and spandrel is 1:1.07. And photo-elastic experiments prove that the maximal shear proportion between mid-points of pier between windows and spandrel is 1:1.13.By the analysis and computation of elastic theory, and validated via experiments, this paper gets to the conclusion that the hazard degree of spandrel verges on that of pier between windows, even surpasses that of pier between windows, and spandrels may probably get destroyed before the piers between windows in earthquakes.Through contrast analysis of experiment result and theoretical computation, this paper works out the handy and practicable computation formula in the anti-quake computation of spandrels:V ≤ 0.48f_vA' Type inside V— Consider the window a wall that earthquake function combination ascendto shear the dint design the value. f_v —The masonry anti- shears the strength design value A' — here is the area of spandrel.The result of this paper can be applied to the appraisal of structural reliability (accreditation of structural reliability, accreditation of hazard buildings and accreditation of structural anti-quake) and structural strengthening for hazard buildings.The feature of this paper lies in using the more scientific structure analysis method (mechanics of elasticity) to replace the relatively crude structure analysis analytical method (mechanics of materials), and thereby this paper corrects the error to be reckoned with which is caused by the latter.