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81.
In situ experiment on retrofit of school buildings by adding sandwich columns to partition brick walls 总被引:1,自引:0,他引:1 下载免费PDF全文
Many significantly strong earthquakes have occurred over the years in Taiwan, which have caused tremendous damage to primary and middle school buildings; the 921 Chi‐Chi earthquake was particularly devastating. According to statistics, 786 schools (1,958 classrooms) were damaged on September 21, 1999 during this earthquake event. The devastation showed that a lack of seismic performance is a common problem for existing school buildings in Taiwan. Therefore, the retrofit of existing school buildings has become an urgent issue in the prevention of possible damage in the future. The retrofit technique of adding sandwich columns to partition brick walls is proposed in this paper, and the feasibility of the proposed method was verified by in situ pushover tests of two real school buildings, one without and one with retrofit. The experimental and analytical results show that the sandwich column itself contributes significantly to the seismic capacity of the examined school building. Moreover, the analytical results yielded conservative capacity curves when compared with the experimental results. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
82.
钢管高强混凝土柱抗震性能的试验研究 总被引:3,自引:2,他引:1
本文对钢管高强混凝土柱进行低周反复水平荷载作用的试验,得到了不同轴压比情况下的滞回曲线及骨架曲线,讨论了钢管高强混凝土柱压弯承载力计算公式的适用性。结果表明,钢管高强混凝土柱具有很高的承载力及良好的抗震性能。 相似文献
83.
This work studies the effect of the curing time on the creep behaviour of a stabilised soft soil, using volumetric and deviatoric creep laws associated with constitutive models. Results of unconfined compressive strength tests for several curing times are used to define the time evolution of the mechanical and creep properties. The models/creep laws are validated by oedometer and triaxial creep tests, for 28 and 90 days of curing. The long-term behaviour of an embankment built on a soft soil reinforced with deep mixing columns shows that the effect of curing time decreases the settlement and increases the improvement factor. 相似文献
84.
区域构造、可溶性岩层和地下水动力条件是岩溶陷落柱形成的3个必备条件。选取刘桥二矿作为研究区,从现有数据中分类提取出区域构造、可溶性岩层和煤层顶底板强富水异常区3个因素,根据底板等高线生成煤层底板坡度图及研究区邻近区域内已探明陷落柱的特征,结合这3个因素,运用GIS叠置分析圈定出4个可能的陷落柱发育区,再经与实际生产情况资料对比,得出巷道揭露的Ⅱ617风巷陷落柱位于第Ⅱ区内。 相似文献
85.
Reduction of structural response to near fault earthquakes by seismic isolation columns and variable friction dampers 总被引:2,自引:2,他引:0
Y. Ribakov 《地震工程与工程振动(英文版)》2010,9(1):113-122
<正>This paper focuses on the investigation of a hybrid seismic isolation system with passive variable friction dampers for protection of structures against near fault earthquakes.The seismic isolation can be implemented by replacing the conventional columns fixed to the foundations by seismic isolating ones.These columns allow horizontal displacement between the superstructure and the foundations and decouple the building from the damaging earthquake motion.As a result, the forces in the structural elements decrease and damage that may be caused to the building by the earthquake significantly decreases.However,this positive effect is achieved on account of displacements occurring in the isolating columns.These displacements become very large when the structure is subjected to a strong earthquake.In this case,impact may occur between the parts of the isolating column yielding their damage or collapse.In order to limit the displacements in the isolating columns,it is proposed to add variable friction dampers.A method for selecting the dampers' properties is proposed.It is carried out using an artificial ground motion record and optimal active control algorithm.Numerical simulation of a seven-story structure shows that the proposed method allows efficient reduction in structural response and limits the displacements at the seismic isolating columns. 相似文献
86.
LI MingQi YANG XiaoYan WANG Hui WANG Qiang JIA Xin & GE QuanSheng Institute of Geographical Sciences Natural Resources Research Chinese Academy of Sciences Beijing China Graduate School of the Chinese Academy of Sciences Beijing Gansu Provincial Institute of Cultural Relics Archaeology Lanzhou Key Laboratory of Western China’s Environmental Systems MOE Lanzhou University 《中国科学:地球科学(英文版)》2010,(5)
Chenqimogou site, located at the south bank of Tao River, is comprised of a large group of graves dated to ~4000 a BP. For its large scale, unique mortuary system, and abundant of typical artifacts, the site was named one of Top Ten Archaeological Discoveries of 2008 in China. Many intact human skeletons have been excavated from the graves. Three teeth from two adult skeletons excavated from graves M187 and M194 were examined. Forty-eight starch grains were retrieved from dental calculus of three teeth. Six... 相似文献
87.
通过对日本抗震设计规范中有关钢筋混凝土框架柱受剪承载力代表性公式的研究,凸现了由经验公式到基于桁架一拱模型建立的发展趋势。对各公式中所包括的影响框架柱受剪承载力的主要因素(如剪跨比、轴压比、配箍率、混凝土强度、纵筋率等)进行了深入讨论,并采用框架柱受剪承载力试验数据考察了各个公式的有效性。 相似文献
88.
89.
The distributions of dissolved and solid phase Fe and Mn have been variously determined in vertical profiles through the water column and sediments at three stations in Bolstadfjord, S.W. Norway. Elevated concentrations of dissolved and suspended particulate Fe and Mn are associated with restricted deep waters as a result of redox reactions and with river discharge. The basin sediments are anoxic throughout but because of the greatly restricted circulation, remobilized Fe and Mn appear to remain predominantly trapped within the fjord. Differentiation of Fe and Mn occurs to the extent that Fe sulphide precipitation is ubiquitous in the sediments whereas the entrapment of Mn, probably through Mn carbonate precipitation, is found only in the sediments of the more seaward basin (maximum Mn content of 1·5% by weight). 相似文献
90.
木薯淀粉羧甲基化合成 总被引:2,自引:0,他引:2
本文是以木薯淀粉为原料进行羧甲基化合物,它是一种采用溶剂分散、助剂对淀粉进行预处理的方法,可以制取高取代度的CMS《 相似文献