【作者】 吴勇；

【导师】 白绍良；

【作者基本信息】 重庆大学 ， 结构工程， 2002， 硕士

【摘要】 根据修订后的地震动参数区划图，《建筑抗震设计规范》(GB50011-2001) 增加了7度半和8度半两个设防烈度区。对应于这两个区的框架结构在内力组合以及配筋上有何规律，与设防烈度为7、 8、 9度时又有什么不同，有必要进行系统的分析和对比。在89规范的基础上，本次规范修订进一步提高了包括层间位移角限值、最小配筋率、柱一梁级差系数等等在内的一系列抗震设计措施。上述抗震措施对结构抗震是否有效，按照新规范设计的7度半、8度半结构在地震作用下能否达到规范预期的抗震设防目标，也有必要通过非线性动力反应分析来予以检验。本文严格按照新规范设计了设防烈度分别为7度半、8度半的两个民用建筑钢筋混凝土典型框架，然后分别对其进行了设防地震作用和罕遇地震作用下的非线性动力反应分析，并在分析中考虑了板筋作用对梁端屈服弯矩的影响。结果表明：① 7度半结构的截面尺寸主要由轴压比决定，绝大部分柱配筋由最小配筋率控制，而8度半结构的截面尺寸由轴压比和最大层间位移角两个因素同时控制，最小配筋率对柱配筋的影响很小。② 当考虑板筋对梁端负弯矩承载力的提高作用时，可在设防烈度地震和罕遇地震作用下分别取每一梁侧四倍、六倍板厚范围作为板的有效宽度。③ 7度半框架在设防烈度地震作用下结构各个杆件均未出铰；在罕遇地震作用下仍然表现出了良好的总体抗震性能，整个结构形成了较为彻底的“梁铰机构”。说明在低烈度区，以最小配筋率为主的抗震措施是有效的，甚至是过于严格的。④ 8度半框架在地震作用下结构总体反应表现良好，形成了以梁端塑性铰为主的耗能机构。这表明新规范对8度半结构采取的抗震措施是有效的，能够实现预期的抗震设计目标。⑤ 7度半结构的柱脚位置和8度半结构的变截面处在反应中均出现了较为不利的情况，有必要加强或增加相应的抗震设计措施以控制其不利反应。更多还原

【Abstract】 According to the refined ground motion parameter districted-figure,7.5 and 8.5 regions of earthquake intensity category are added in new seismic design code of China. It is worthy to analyze systemically what is the characteristic in internal force combination or reinforced design to frames of two regions and what is the difference in results while taking 7,8 and 9 regions into account.On the base of codes in 1989,a series of seismic measures are improved in new codes,such as limit of inner-storey drift angle,minimum reinforced rate,column-beam moment magnification coefficient and moment magnification factor at the column base,etc. It is also necessary to verify by nonlinear dynamic analysis whether the measures above are effective and whether the anticipative earthquake-resistance aims can be achievable for frames in 7.5 and 8.5 regions.It begins with designing two representative reinforced concrete public frames according to new codes in this paper,and carries out nonlinear dynamic analysis by inputting ground motions at the intensity of intermediate earthquake and rare earthquake actions. The slab-bars effect on yield strength of beams is involved in analysis. The conclusions are as following:(a) The element dimensions of frames in 7.5 regions are determined mainly by axial compressive ratio. The reinforcements in most columns are dominated by the minimum reinforcement rate. And the element dimensions of frames in 8.5 region are determined by both axial compressive ratio and maximum inner-storey drift angle. The minimum reinforcement rate has little effect on reinforcement in columns.(b) When considering the bars in slab participate in beams against negative flexure,four or six times slab-thickness on each side of web can be defined as the effective flange width of slab by intermediate or rare earthquake actions.(c) There are no plastic hinges in frames of 7.5 regions by intermediate earthquake action. And favorable general seismic capacity behaves in rare earthquake action. The whole structure forms a relatively exhaustive "beam-hinges plastic mechanism ". It demonstrates that the seismic measures in low intensity regions,mainly means minimum reinforcement rate,is effective and even excessive strict.(d) The structure in 8.5 region demonstrates a favorable response under earthquake action and forms a well energy-consuming mechanism. It indicates that the seismic measures to 8.5 region is effective and can achieve anticipative seismic aims.(e) Since the results demonstrate a relatively unfavorable response at column basein 7.5 region structure and in column-tapered of 8.5 region structure,it is necessary to strengthen some involved seismic measures to better the unfavorable response.更多还原