钢筋混凝土掉层框架结构抗连续性倒塌性能研究

发布时间：2018-01-05 04:14

本文关键词：钢筋混凝土掉层框架结构抗连续性倒塌性能研究　出处：《重庆大学》2014年硕士论文　论文类型：学位论文

【摘要】：因1968年英国“Ronan Point”事故，结构抗连续倒塌问题备受关注，40多年来各国学者对结构抗连续倒塌做了大量研究并得出许多重要成果，但与掉层框架结构抗连续倒塌相关的研究几乎没有。掉层框架结构是山地建筑结构中较为典型的结构形式，不等高接地使得该类结构具有竖向不不规则性，且上接地层柱底约束差异导致柱的侧移刚度不同，这使得掉层框架结构抗连续性倒塌性能可能不同于一般的框架结构。另一方面，边坡失稳也可能导致结构发生倒塌。基于此，有必要开展掉层框架结构的抗连续倒塌性能的研究。本文主要工作如下： ①总结了结构抗连续倒塌的设计和分析方法，重点分析了拆除构件法并指出应用时应注意的关键问题，同时对其进行了校验。 ②参照GSA2003、应用SAP2000分析软件，采用拆除构件法从掉层层数、掉层跨数、上接地方式、抗震设防烈度及边坡失稳五方面对掉层框架结构抗连续倒塌性能的影响进行了研究。 ③基于掉层框架结构的结构及受力特点，提出了增设支撑、提高局部楼层梁的配筋以及掉层梁与挡墙连接三种提高抗连续倒塌能力的措施，并对这些措施的有效性进行了分析，给出了相应的设计建议。本文得到的主要结论有： ①掉层框架结构抗连续倒塌性能较一般结构更不利，，其抗连续倒塌能力变化规律为：总层数一定时，随掉层层数增加而降低；总跨数一定时，随掉层跨数增加而提高；上接地柱底刚接结构比柱底铰接结构的抗连续倒塌能力弱；内柱失效结构发生连续倒塌破坏风险最大，对结构抗连续倒塌起控制作用的构件是与失效柱上部相连的梁。 ②按6度抗震设防烈度设计的掉层框架结构的抗连续倒塌能力不足，随着抗震设防烈度的提高，控制框架结构配筋的内力组合由非地震作用效应参与组合转为地震作用效应参与的组合，结构的抗连续倒塌能力明显提高。 ③对于设置有支撑的掉层框架结构，只有失效柱位于支撑所在跨内时，结构抗连续倒塌能力才能得到提高；支撑设置于失效柱以上一层时，支撑对结构抗连续倒塌能最有利，随着支撑设置位置的升高，支撑对结构抗连续倒塌能力提高效果逐渐降低。 ④对于按6度（0.05g）抗震设防设计的掉层框架结构，当上接地以上30%的楼层及与上接地面平齐的楼层的梁配筋量提高30%~35%时，掉层框架结构基本具备抗连续倒塌能力；相对下接地柱失效而言，梁配筋量的增加对提高上接地柱失效剩余结构抗连续倒塌能力作用更明显。 ⑤下接地部分的梁与挡墙连接方式采用刚接对提高结构连续倒塌能力的作用比采用铰接的明显，但其提高作用仅对下接地临挡墙的一榀框架柱破坏情况有效，且随着上接地以上层数增加，掉层梁与挡墙刚接连接对结构抗连续倒塌能力的提高作用越来越不明显。
[Abstract]:Due to the "Ronan Point" accident in Britain in 1968, the problem of continuous collapse of structures has attracted much attention. For more than 40 years, many scholars have done a lot of research on the continuous collapse of structures and obtained many important results, but there is almost no research related to the continuous collapse of falling frame structures. Falling floor frame structure is a typical structure form in mountain building structure. Different height earthing makes this kind of structure not irregular in vertical direction, and the lateral stiffness of column is different due to the constraint difference of upper grounding layer column bottom. This makes the continuous collapse behavior of the falling floor frame structure different from that of the general frame structure. On the other hand, the slope instability may also lead to the collapse of the structure. It is necessary to study the continuous collapse resistance of falling floor frame structure. The main work of this paper is as follows: The main contents are as follows: 1. The design and analysis methods of continuous collapse resistance of structures are summarized. The method of removing components is analyzed and the key problems in application are pointed out. At the same time, the key problems are verified. (2) referring to GSA2003, using SAP2000 analysis software, adopting the method of removing component from falling layer number, falling layer span number, and grounding mode. The effects of seismic fortification intensity and slope instability on the continuous collapse resistance of floor-falling frame structures are studied. 3. Based on the structure and stress characteristics of falling floor frame structure, three measures are put forward to improve the ability to resist continuous collapse by adding support, improving the reinforcement of local floor beam and connecting the falling floor beam and retaining wall. The effectiveness of these measures is analyzed and the corresponding design suggestions are given. The main conclusions of this paper are as follows: (1) the continuous collapse resistance of the falling floor frame structure is more unfavorable than that of the general structure, and the variation rule of its continuous collapse resistance ability is as follows: when the total layer number is fixed, it decreases with the increase of the falling layer number; When the total span number is constant, the total span number increases with the increase of the falling layer span number. The resistance to continuous collapse of the rigid-jointed structure at the bottom of the above earthing column is weaker than that of the hinged structure at the bottom of the column. The failure risk of the failure structure of internal column is the greatest. The member that controls the continuous collapse of the structure is the beam connected to the upper part of the failure column. (2) the continuous collapse resistance of the falling floor frame structure designed according to the 6 degree seismic fortification intensity is insufficient, with the increase of seismic fortification intensity. The combination of internal forces controlling the reinforcement of frame structure is changed from non-seismic effect to seismic effect, and the ability of resisting continuous collapse of frame structure is improved obviously. (3) for the falling floor frame structure with bracing, the anti-collapse ability of the structure can be improved only when the failure column is located in the span of the bracing; When the bracing is located above the failure column, the bracing is most favorable to the continuous collapse energy of the structure. With the increase of the position of the bracing, the effect of improving the ability of the bracing to resist the continuous collapse decreases gradually. 4 for the falling floor frame structure which is designed according to the 6 degree 0. 05 g) seismic fortification, the amount of beam reinforcement on the 30% floor above the ground level and the floor level with the upper ground is increased by 30 ~ 35 times. The falling floor frame structure basically has the ability to resist continuous collapse. Compared with the failure of the lower grounding column, the increase of beam reinforcement is more obvious to improve the continuous collapse resistance of the residual structure with the upper grounding column failure. (5) the connection between beam and retaining wall in the lower earthing part is more effective than hinge connection in improving the continuous collapse ability of the structure, but it is only effective for the failure of a frame column of the next earthing temporary retaining wall. With the increase of the number of layers above the ground, the effect of the rigid connection between the falling beam and the retaining wall on the continuous collapse resistance of the structure is less and less obvious.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU375.4;TU312.3

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