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The present work reports on an in situ experimental test campaign carried out on abandoned traditional masonry houses after the 9th July 1998 earthquake that seriously hit the Faial island of Azores. For the testing purposes, an experimental test setup was developed based on a self‐equilibrated scheme, which is herein described reporting on the advantages and drawbacks of this in situ test setup. Five specimens were tested aiming at characterizing the out‐of‐plane behavior of stone masonry walls and strengthening solutions recommended for post‐earthquake interventions. A detailed comparison between solutions' efficiency is presented including a cost vs benefit analysis. In order to assess the efficiency of the developed test setup for other applications on stone masonry walls, an in‐plane test on an existing URM panel is also presented. Several related issues are discussed, namely the advantages of dealing with the real boundary conditions and the capacity of providing valuable information of the response, as well as a detailed analysis of the obtained results. The authors believe that this work provides an increase in knowledge on the seismic behavior of the existing masonry constructions, resulting from the development of an in situ test setup and the efficiency quantification of strengthening solutions. Therefore, the work is thought to positively contribute for the preservation of architectural heritage and for its seismic vulnerability reduction. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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加强地质工作为安徽奋力崛起提供基础保障 总被引:1,自引:1,他引:0
文章分析了加强地质工作是安徽奋力崛起的基础保障,阐明了加强地质工作的关键是要充分发挥政府的主导作用,重点是要继续发挥地勘队伍的主力军作用. 相似文献
45.
某中小学教学楼为典型的80年代建造的砌体教学楼,鉴定结果显示基础稳定,上部结构材料强度不足,部分构造设置不合理。在结构抗震加固再设计中,从概念上分析结构加固的合理性;合理地确定地震作用影响系数,对加固前后的结构进行整体计算分析;对重要及复杂的部分节点进行补充设计。 相似文献
46.
The application of fiber reinforced plastic(FRP),including carbon FRP and glass FRP,for structural repair and strengthening has grown due to their numerous advantages over conventional materials such as externally bonded reinforcement(EBR) and near-surface mounted(NSM) strengthening techniques.This paper summarizes the results from 21 reinforced concrete beams strengthened with different methods,including externally-bonded and near-surface mounted FRP,to study the strain coordination of the FRP and steel rebar of the RC beam.Since there is relative slipping between the RC beam and the FRP,the strain of the FRP and steel rebar of the RC beam satisfy the quasi-plane-hypothesis;that is,the strain of the longitudinal fiber that parallels the neutral axis of the plated beam within the scope of the effective height(h 0) of the cross section is in direct proportion to the distance from the fiber to the neutral axis.The strain of the FRP and steel rebar satisfies the equation:ε FRP =βε steel,and the value of β is equal to 1.1-1.3 according to the test results. 相似文献
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针对某病害站场路基,根据其变形规律对其基础进行补勘,分析病害原因,在此基础上提出岩溶地基加固补强方案:①补注浆加固岩溶地基和基岩顶面土体;②高压旋喷加固补强原复合地基;③低压注浆加固垫层及其以上3~5 m路基填土层;④侧向补注浆帷幕加固地基;⑤建立路基变形监测系统,评估加固补强效果。加固补强后地基沉降量和复合地基承载力特征值的理论计算值分别为12.4 mm和455 kPa,满足设计要求。现场监测结果表明,补注浆加固岩溶地基及其顶面土体后,站场路基变形减缓;旋喷桩和低压注浆加固区竣工后,路基呈均匀性沉降变形,变形速率急剧变小;竣工6个月后,路基变形趋于稳定,综合验证了加固补强方案的正确性和有效性。 相似文献
49.
截面层次的恢复力模型能兼顾计算精度与计算效率,为此在梁-柱单元中得到了广泛的应用。但目前给定"轴力-弯矩-曲率"的截面恢复力模型无法灵活考虑轴力与弯矩的耦合作用;采用屈服面的截面恢复力模型尚未考虑截面强化效应。提出了基于屈服面的截面随动强化恢复力模型及其积分方法,首先依据截面屈服面建立了截面随动强化恢复力模型,然后依托塑性理论,进行截面状态确定和本构关系积分。最后利用所提出的恢复力模型进行了悬臂柱的静力往复分析。结果表明:(1)所选用的截面恢复力模型能很好考虑轴力存在对弯矩的影响;(2)该模型具有随动强化的特性;(3)在精度上接近纤维截面所用的单轴材料随动强化模型。 相似文献
50.
Lili Xu Jörg Renner Marco Herwegh Brian Evans 《Contributions to Mineralogy and Petrology》2009,157(3):339-358
We extended a previous study on the influence of Mg solute impurity on diffusion creep in calcite to include deformation under
a broader range of stress conditions and over a wider range of Mg contents. Synthetic marbles were produced by hot isostatic
pressing (HIP) mixtures of calcite and dolomite powders for different intervals (2–30 h) at 850°C and 300 MPa confining pressure.
The HIP treatment resulted in high-magnesian calcite aggregates with Mg content ranging from 0.5 to 17 mol%. Both back-scattered
electron images and chemical analysis suggested that the dolomite phase was completely dissolved, and that Mg distribution
was homogeneous throughout the samples at the scale of about two micrometers. The grain size after HIP varied from 8 to 31 μm,
increased with time at temperature, and decreased with increasing Mg content (>3.0 mol%). Grain size and time were consistent
with a normal grain growth equation, with exponents from 2.4 to 4.7, for samples containing 0.5–17.0 mol% Mg, respectively.
We deformed samples after HIP at the same confining pressure with differential stresses between 20 and 200 MPa using either
constant strain rate or stepping intervals of loading at constant stresses in a Paterson gas-medium deformation apparatus.
The deformation tests took place at between 700 and 800°C and at strain rates between 10−6 and 10−3 s−1. After deformation to strains of about 25%, a bimodal distribution of large protoblasts and small recrystallized neoblasts
coexisted in some samples loaded at higher stresses. The deformation data indicated a transition in mechanism from diffusion
creep to dislocation creep. At stresses below 40 MPa, the strength was directly proportional to grain size and decreased with
increasing Mg content due to the reductions in grain size. At about 40 MPa, the sensitivity of log strain rate to log stress,
(n), became greater than 1 and eventually exceeded 3 for stresses above 80 MPa. At a given strain rate and temperature, the
stress at which that transition occurred was larger for samples with higher Mg content and smaller grain size. At given strain
rates, constant temperature, and fixed grain size, the strength of calcite in the dislocation creep regime increased with
solute content, while the strength in the diffusion creep regime was independent of Mg content. The results suggest that chemical
composition will be an important element to consider when solid substitution can occur during natural deformation. 相似文献