影响高层建筑嵌固的地下室侧向刚度影响范围研究

发布时间：2018-10-05 21:02

【摘要】：随着我国高层建筑的迅速发展,嵌固端选取的理论研究工作的重要性日渐凸显。嵌固端的合理选取是结构设计人员关注的核心问题之一,因为其直接关系到结构计算模型与工程实际受力状态之间的符合程度。嵌固端选取的影响因素很多,国内外学者对其做了大量的研究工作,这些研究表明地下室侧向刚度之比(嵌固层的侧向刚度与相邻上层侧向刚度之比)是影响嵌固端选取的决定因素。然而,关于地下室外的回填土对地下室侧向刚度影响的有无及其影响范围的理论研究相对较少,故本研究立足于此,对其进行进一步的实际探讨和理论分析。本文以湖北省宜昌市某工程为算例,进行了以下几方面的探讨和分析： (1)从有无地下室、基础结构形式、基础埋置深度、建筑高度和高宽比四个方面定性分析嵌固端的选取； (2)比较嵌固端位置的不同对结构周期、位移、弯矩以及嵌固层与相邻上层的侧向刚度之比的影响； (3)利用结构分析软件,通过考察嵌固层位移和刚度K的变化,分析回填土对结构的约束作用； (4)改变地下室的外扩倍数n,对不同范围内的地下室侧向刚度进行对比分析,并比较结构的动力特性、变形特性、内力特性。得出如下结论： (1)对于本工程而言,将结构嵌固端设在地下一层底板能够满足刚度要求,同时也较经济。 (2)将嵌固端取在地下二层底板,地下室顶板梁端最大弯矩较嵌固端取在地下一层底板减幅较小,仅为0.51%-0.95%,嵌固层与相邻上层的刚度比较嵌固端取在地下一层底板提高的幅度亦不大,为3.82%；嵌固端的不同对结构的周期和顶层位移影响不大,周期相对于嵌固端取在地下室顶板增大了0.54%～1.22%,顶层位移相对于嵌固端取在地下室顶板增大了0.91%-1.50%； (3)当“土层水平抗力系数的比例系数m”满足0m10时,有必要合理的考虑地下室外回填土对结构的约束作用；当m10时,地下室外回填土对结构的约束作用被无限放大了。因此,为了使模型切合工程实际,需要合理的考虑m的取值； (4)回填土对结构约束作用的大小对地下室顶板的水平位移影响很大,高达91.34%,对地上二层底板的水平位移影响可达25%,表明地下室外回填土约束作用的大小与研究对象的位置有关,离嵌固端的位置越远,其约束作用越小； (5)改变地下室外扩倍数n,按剪切刚度计算的地下一层底板的相对侧向刚度K=1.2,而且不会随着地下室外回填土质量的变化发生改变；按地震剪力和地震层间位移比计算的地下一层底板的相对侧向刚度K,随着地下室外扩倍数n的增大而增大,而且随着m值的增大,其增幅逐渐上升； (6)改变地下室外扩倍数n,结构周期在n=2时出现拐点达到最大值,顶层位移在n=2时出现拐点达到最小值,嵌固层梁端弯矩在n≥2以后,增幅减小,说明地下室侧向刚度的影响范围可以近似取2倍地下室层高。
[Abstract]:With the rapid development of high-rise buildings in our country, the importance of theoretical research on the selection of embedded solid ends is becoming more and more obvious. The rational selection of embedded solid end is one of the core problems of structural design personnel, because it is directly related to the degree of compliance between the structural calculation model and the actual stress state of the project. Many researchers have done a lot of research work. These studies show that the ratio of the lateral stiffness of the basement (the ratio of the lateral stiffness of the embedded layer to the lateral stiffness of the adjacent upper layer) is the result of the selection of the embedded solid end. However, there are relatively few theoretical researches on the influence of the backfill soil outside the basement on the lateral stiffness of the basement and its influence range. Therefore, this study is based on this. On the basis of a certain project in Yichang City, Hubei Province, the following aspects are carried out Discussion and analysis of surface: (1) From the presence or absence of basement, foundation structure form, foundation embedded depth, building height and aspect ratio the selection of the solid ends of the surface qualitative analysis; (2) comparing the different pairs of structural periods, displacements, bending moments and embedding layers of the embedded end positions the influence of the ratio of the lateral stiffness to the adjacent upper layer; (3) utilizing structural analysis software to investigate the displacement and rigidity of the embedded layer According to the change of K, the restraining effect of the backfill on the structure is analyzed; (4) the external expansion factor n of the basement is changed, and the lateral rigidity of the basement in different ranges is compared. Analyze and compare the knot The dynamic characteristics, deformation characteristics and internal force characteristics of the structure are obtained. The following conclusions are obtained: (1) For the Project, According to the invention, the structure embedding end is arranged on the underground floor, and the rigidity requirement is met, and meanwhile, the structure is relatively economical. (2) the embedded solid end is taken on the underground two-layer bottom plate, the maximum bending moment at the top plate beam end of the basement is smaller, and only 0. 51%-0. 95%, the embedded solid layer and the bottom plate of the underground floor are smaller, The stiffness of the adjacent upper layer is less than that of the bottom plate in the underground floor, and it is 3.82%; the different effect on the structure and the displacement of the top layer is not big, and the period is increased by 0. 54% ~ 1 with respect to the fixed end. For 22%, the top-level displacement increases from 0. 91%-1. 50% relative to the fixed end. (3) When

"Proportioncoeffecient m of soil layer horizo When the ntal resistance coeffecient" meets the 0m10, it is necessary to reasonably consider the outside of the basement The effect of backfill on the structure; when m10 is m10, the external backfill of the basement shall be connected to the junction. Therefore, in order to adapt the model to the practical engineering, it is necessary to consider the value of m reasonably, and (4) the size of the backfill soil on the structural restraint effect. The horizontal displacement of the top plate of the basement is great, up to 91.34%, and the effect of horizontal displacement of the bottom plate on the ground can reach 25%, The constraint effect of backfill soil outside the basement is related to the position of the research object, the farther from the fixed end, the restraint action The smaller it is, (5) change the external expansion factor n of the basement, the relative lateral stiffness of the underground floor slab calculated by the shear stiffness K = 1. 2, and will not change with the change of the quality of the backfill soil outside the basement, and the underground space calculated by the displacement ratio between the seismic shear force and the seismic layer. The relative lateral stiffness K of a floor slab increases with the increase of the expansion factor n in the basement, and increases with the increase of m value. When n = 2, the inflection point reached the maximum value, and the top-level displacement showed an inflection point when n = 2.
【学位授予单位】：武汉理工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU973.2

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