底层框架抗震墙砖房结构设计中若干问题的探讨

本文通过对底层框架抗震墙砖房结构设计中的受力变形特性,结构选型;抗震墙的布置,底层现浇楼板厚度及配筋;牝二层与底层的侧移刚度比;地震力增大系统地震剪力在抗震墙和框架柱间的分配,底层框架梁上竖向荷载的取值,次梁对主梁的扭矩圈梁和构造柱的设等问题进行了探讨,供设计参考。     

底层框架抗震砖房的设计探讨

底层框架抗震墙砖房是下部为框架,上部为砖混的一种特殊的结构体系,在设计中需要一些特殊的考虑。     

底部框架一抗震墙房屋抗震设计

根据国内外近年来的地震破坏的特点及规范的要求，对底部框架一抗震墙房屋抗震设计的结构体系布置、房屋的平立面布置、房屋的高度、房屋的高宽比、第二或第三层与底部的侧移刚度比、抗震墙的最大间距、底部钢筋砼抗震墙的高宽比的具体要求进行了全面阐述。     

底层框架砖房柱截面尺寸和抗震墙数量的确定

根据国际（GBJ11－89）规定的柱的轴压比、层间相对位移、层刚度比、抗震墙的最小厚度和最大间距等限值，提出了确定底层框架砖房柱截面尺寸和抗震墙数量的一种简便方法。     

浅谈框架结构的抗震设计

介绍了框架结构中对抗震设计的要求,从框架结构的抗震等级、结构延性、节点核心区设计、构造措施等方面进行了论述,指出为提高框架抗震能力,在实际工程中抗震概念设计尤为重要。     

底层框架砌体结构抗震设计分析

底层框架砌体结构是指仅部分砌体纵横墙落地,在底层大空间位置采用框架的混合建筑形式。底层框架砌体结构具有一定的经济优势,但这种结构体系为上刚下柔,抗震性能较差。从刚度、强度、延性几个方面对这种结构体系抗震性能进行了分析,提出了抗震概念设计的几点建议。     

底层框架砖房抗震设计

本文对底层框架砖房的抗震设计基本要求、地震作用分析、抗震验算及其构造措施等进行了较详细的阐述.     

多层砌体房屋设计中的抗震构造措施

介绍多层砌体建筑选址、平立面布局、层高和高度控制、承重方式、构造柱和圈梁的设置、楼屋盖形式、楼梯间的加强措施、砂浆强度等抗震构造措施,以增强多层砌体房屋的抗震性能。     

轻质混凝土拼装墙板填充钢框架协同抗震性能试验研究

为了研究墙板与钢框架结构之间的协同抗震性能,对采用不同墙框连接节点的轻质混凝土拼装墙板填充钢框架进行了低周往复荷载试验。通过对比试件的承载力、滞回性能、刚度、耗能以及延性性能,探讨了轻质混凝土拼装墙板及其整体性对结构抗震性能的影响。结果表明:填充墙板钢框架结构的最终破坏形态以墙板挤压开裂,框架梁柱端部翼缘屈曲为主;轻质混凝土拼装墙板与钢框架协同工作,有利于提高结构整体的承载力和变形能力,减轻钢框架在平面内的屈曲破坏;与刚性节点相比,采用柔性节点连接墙板与钢框架对结构的承载力、层间刚度和耗能能力更为有利;增强拼装墙板的整体性,有助于提高结构整体刚度、变形和耗能能力。研究结果可为轻质混凝土拼装墙板填充钢框架结构的抗震设计提供参考。      

有关钢筋砼框架结构中梁柱抗震构造要求的体会

本文论述了抗震钢筋砼框架结构中,合理框架问题。而合理框架结构,主要是梁柱的关系,以及梁柱的具体构造。     

刚架替代框架中框架梁的结构设计

在底层框架上部砖混的建筑结构中,以刚架替代框架中的框架梁,刚架降蔽在砖混墙体内。此结构设计既可以增大建筑空间,又可以满足层高和净空的要求。     

带吊车门式刚架轻型钢结构厂房的设计与分析

以实际工程为背景，采用门式刚架轻型房屋钢结构设计规程，对带吊车门式刚架、吊车梁、抗风柱及基础的受力特点、设计方法进行分析，解决了设计中所遇到的问题。     

框架结构墙体拉结筋设置方法的改进

框架结构施工时,需要在墙体上设置拉结筋,以起到拉结墙体的作用,其目的是为了增强砖墙体和框架主体的整体刚度和稳定性。对框架结构墙体拉结筋的常见施工方法进行了分析和讨论,结合工程实际情况,找出了一种更加经济有效的施工方法。     

钢结构厂房中墙架系统及节点优化设计

介绍了钢结构厂房墙架采用矩形钢管连续墙架梁的设计方法及简支墙架梁的优化设计。     

Experimental Evaluation of a Sacrificial Seismic Fuse Device for Masonry Infill Walls

Presented herein are the details and results of an experimental study conducted to evaluate the performance of a proposed infill wall fuse system. The purpose of this system, referred to as the seismic infill wall isolator subframe (SIWIS) system, is to prevent damage to columns or infill walls due to infill-frame interaction through a “sacrificial” component or a “structural fuse.” The SIWIS system conceptually consists of two vertical and one horizontal sandwiched light-gauge steel studs with SIWIS elements in the vertical members. The experimental study presented here involves the in-plane lateral load testing of a two-bay three-story steel frame in three forms of bare frame, infilled braced frame, and pinned frame equipped with the proposed SIWIS device. In addition, a brick wall in-plane strength test and a series of component tests on three different designs for fuse element were conducted. In the conducted tests, the suggested technique initially engages the infill walls in seismic resistance of the frame, but ultimately isolates them. It is concluded, thus, that the proposed fuse system has the potential for the development of an effective way to reduce earthquake damage in framed buildings with infill walls.     

Evaluation of Distress in Supports of Hyperbolic Paraboloid Shell

A church building structure, composed of a saddle-type hyperbolic paraboloid concrete shell roof supported by buttresses and brick masonry walls, was constructed in 1963. At one corner of the structure, the perimeter of the roof shell projects beyond the exterior building walls to form a canopy over the main entrance. This canopy is partially supported by two brick masonry fin walls that project outward from the main building walls. At the time of original design, closed-form methods (equations) were the only practical way of analyzing this shell structure. However, the configuration of the roof shell was not consistent with detailing requirements of the closed-form methods. After 36?years of service, the fin walls had bowed significantly, were exhibiting wide cracks, had slipped laterally with respect to the roof shell, and were in danger of collapse. The writer led an investigation team that developed a finite element model of the church structure, studied the behavior of the church structure when subjected to applied loads and temperature changes, and developed repairs to restore structural integrity and serviceability.     

Collapse Study of an Unreinforced Masonry Bearing Wall Building Subjected to Internal Blast Loading

A blast test was conducted inside a conventional, two-story, unreinforced, brick, bearing wall building scheduled to be demolished. A credible explosive device was placed inside the building on the ground floor and was detonated to investigate whether or not the building would collapse. The measured blast pressures, key material properties of the structure, and the structural configuration were used as input parameters to a single-degree-of-freedom software program, the single-degree-of-freedom blast effects design spreadsheet (SBEDS), commonly used in the United States to model unreinforced masonry walls subjected to blast loading. The net effect of overburden loads on the ground-floor bearing walls, including uplift by blast pressures on the ground-floor ceiling, was considered when investigating the validity of an appropriate resistance function (available in SBEDS) that defines out-of-plane bearing wall response. Comparisons were made between analytical and experimental permanent wall deflections and two alternatives, a simple displacement-based criterion and a resistance criterion, were used to estimate the building’s state relative to its estimated collapse limit state. It was found that SBEDS was able to model the experimental deflections quite well if effective input parameters were carefully considered. As a result, analytical and experimental determinations of the structure’s state were also in good agreement.     

砖混结构墙体二次开洞对抗震性能的影响

本文研究了砖混结构墙体中二次开洞现象,说明它可以改变墙体的侧向刚度和破坏结构的整体性,尤其是发迹了地震剪力在各受剪力的墙体中的分配,由此直接影响了原设计结果。     

Responses of Buildings with Different Structural Types to Excavation-Induced Ground Settlements

This paper compares the responses of buildings with different structural types on shallow foundations subjected to excavation-induced ground settlements and provides a better understanding of the complex soil-structure interaction in building response. Investigated structures include brick-bearing structures, open-frame structures, and brick-infilled frame structures. These structures are often encountered near a construction area, and the different structures may show very different behaviors to excavation-induced ground settlements. In this research, numerical studies were carried out to evaluate the responses of single brick-bearing walls and frame structures (both open and brick infilled) subjected to an identical progressive ground settlement and to provide key features of building responses in different soil conditions, structure conditions, and structural types. Each structure, which is four stories high, was modeled numerically with two different soil conditions, and the response was compared among other types of structures and between elastic and crackable conditions for the brick-bearing and brick-infilled frame structures. Comparison of building responses was investigated by using distortions and crack damages induced to the structures by excavation-induced ground settlements. The structures were modeled by using the two-dimensional (2D) universal distinct element code (UDEC 3.1) in which each brick unit was modeled as a separate unit, with the contacts between brick units having stiffness and strength characteristics of mortar. The numerical studies indicated that the structural response to excavation-induced ground settlements is highly dependent on structural type, cracking in a structure, and soil condition; therefore, their effects should be considered to better assess building response to excavation-induced ground settlements.     

Seismic Stability of Soil Retaining Walls Situated on Slope

Many soil retaining walls, which were used to stabilize highway embankments constructed on hillside, were severely damaged during the major earthquake (Chi-Chi earthquake, ML = 7.3) on September 21, 1999 in Taiwan. We investigated two typical cases of soil retaining wall damage using survey, soil borings and soil tests. To this end we developed a new pseudo-static method to evaluate the seismic stability of retaining walls situated on slope. Sliding failure along the wall base and bearing capacity failure in the foundation slope were considered in the new pseudo-static method. Results of the analysis showed that seismic stability of the wall against bearing capacity failure may be greatly overestimated when the inertia of soil mass is not taken into account. The analytical results also showed that sliding failure along the wall base occurs prior to the bearing capacity failure of the wall situated on a gentle slope at Site 1. The opposite is true for the wall situated on a steep slope at Site 2. For soil retaining walls constructed on slope, sliding failure of the wall may occur under small input horizontal ground acceleration when the passive resistance in front of the wall is not effectively mobilized. This highlights the importance of improving the strength of backfilled soils in the passive zone when constructing soil retaining walls on slope. The results obtained in the present study also suggest a modification of the current design considerations for soil retaining walls situated on slope.