配BFG蒸压加气混凝土砌块砌体基本力学性能数值模拟     

陈东方  熊立红  陈国武  罗明康 《地震工程与工程振动》2020,(2):216-226

将蒸压加气混凝土(AAC)砌体填充墙采用薄灰缝专用砂浆砌筑,并在灰缝中配置玄武岩纤维格栅(BFG),可以提高墙体的抗压强度和延性。为了研究配BFG的AAC砌块砌体的基本力学性能,设计了9组27个试件进行抗压和抗剪试验。在试验的基础上,首先分析了砌体的抗压和抗剪性能,给出抗压上升段本构方程和抗压、抗剪强度建议公式;其次运用ABAQUS对砌体的抗压和抗剪性能进行模拟,通过比较模拟结果与试验结果,验证了有限元模型的合理性;最后分析了模型受压时的应力-应变关系,给出抗压下降段本构方程。研究表明:荷载施加处,接触面上剪应力集中是砌体通缝抗剪破坏的主要原因;本构方程可为配BFG蒸压加气混凝土砌体填充墙抗震性能的研究提供参考。  相似文献   

海水海砂混凝土双K断裂参数的确定   总被引：1，自引：1，他引：0  

臧朝会  杨树桐  金亮亮 《海洋工程》2019,37(4):142-150

采用尺寸为515 mm×100 mm×100 mm初始缝高比从0.1变化至0.8的三点弯曲梁试件,利用试验测得起裂荷载Pini、最大荷载Pmax及对应的裂缝口张开位移CMODc等参数,研究了缝高比a0/h对海水海砂混凝土双K断裂参数的影响。并以相同配合比的淡水河砂梁作为对照组,进一步研究了海砂海水混凝土双K断裂参数与普通混凝土之间的关系。结果发现海水海砂混凝土断裂参数在a0/h=0.25～0.7范围内时可以认为是一常数;海水海砂混凝土梁断裂参数比相同配合比情况下的淡水河砂梁大且对边界影响更加敏感。  相似文献   

Effects of the peat acid digestion protocol on geochemically and morphologically diverse tephra deposits     

Alistair J. Monteath  Alex E. Teuten  Paul D. M. Hughes  Stefan Wastegrd 《第四纪科学杂志》2019,34(4-5):269-274

Tephra shards for electron probe microanalysis are most efficiently extracted from peat using acid digestion, which removes organic material that hinders density separation methods. However, strong acids are known to alter glass chemical compositions, and several studies have examined how acid digestion affects rhyolitic volcanic glass. The focus on rhyolitic tephra in these studies leaves considerable uncertainty, as the dissolution rates of natural glasses (including tephra) are determined by the chemical composition and surface area/volume ratio, both of which vary in tephra deposits. Here, we use duplicate samples of basaltic, trachydacitic and rhyolitic tephra to examine physical and geochemical alteration following acid digestion. Scanning electron microscope imagery reveals no discernible degradation of glass surfaces, and electron probe microanalysis results from duplicate samples are statistically indistinguishable. These findings suggest the acid digestion protocol for organic peats does not significantly alter glass geochemistry regardless of shard morphologies or geochemical compositions.  相似文献   

湿陷性黄土边坡预应力锚索耐久性与改善措施研究          下载免费PDF全文

郭红东  白杨  畅才源 《甘肃地质》2021,(2):59-65

随着预应力锚索在湿陷性黄土边坡加固工程中的广泛应用,其耐久性问题就变得日益突出,湿陷性黄土边坡预应力锚索出现了较多因预应力损失而引起的失效事故。基于湿陷性黄土边坡预应力锚索运行现状进行研究,研究表明:黄土腐蚀性对边坡预应力锚索耐久性影响微弱,黄土湿陷性和地质条件变化对边坡预应力锚索耐久性影响显著;通过采用加强排水措施、提升浅部注浆工艺和注重运行维护等措施可以改善湿陷性黄土边坡预应力锚索耐久性;改善后的预应力锚索在监测期内处于平稳波动的服役状态,运行效果良好。本研究以期为湿陷性黄土边坡预应力锚索的设计、施工和运行维护等提供借鉴。  相似文献   

对“白加白”改造旧水泥砼路面实施方案的探讨     

何勇兵 《安徽地质》2011,21(3):228-230

G318怀宁段路面改善工程设计方案为旧水泥砼路面加铺水泥砼路面(简称"白加白"),在安庆市公路系统尚属首次实施,在我省亦无成功的实践经验可直接借鉴。为此,安庆市公路局专门成立了科研小组,并与浙江大学合作,以"白加白改造旧水泥砼路面方案的研究"为课题,将G318怀宁段作为实践项目,申报2010年度安徽省交通科技项目。笔者作为小组三位主要成员之一,全过程参与该项目的建设与管理。现就该方案的实践成果进行一次全面系统的总结,并就有关技术问题进行探讨。  相似文献   

锦屏一级水电站坝基无盖重固结灌浆施工工艺探讨   总被引：2，自引：0，他引：2       下载免费PDF全文

杨世伟  李德勇 《探矿工程》2011,38(8):56-58,63

锦屏一级水电站大坝由于基础层混凝土仓面面积大,温控要求严格、间歇期短,固结灌浆施工与坝体混凝土温控存在较大矛盾,主要采取无盖重固结灌浆加有盖重补强固结灌浆及引管的方式进行。主要就无盖重固结灌浆主要存在问题进行了分析和探讨。  相似文献   

锦屏二级水电站隧洞无盖重高压固结灌浆试验   总被引：3，自引：0，他引：3       下载免费PDF全文

邹刚 《探矿工程》2011,38(5):74-77

水工隧洞高压固结灌浆的目的是加固隧洞围岩、封闭隧洞周边岩体裂隙,提高隧洞围岩的整体性和抗变形能力,增强围岩抗渗能力和长期渗透稳定性。主要介绍了引水隧洞在未进行混凝土衬砌的条件下实施高压防渗固结灌浆施工的试验及其成果,为该类洞段灌浆设计和施工提供依据。  相似文献   

Modeling of RC columns strengthened with RC jackets     

A. P. Lampropoulos  S. E. Dritsos 《地震工程与结构动力学》2011,40(15):1689-1705

Constructing concrete jackets is a common technique when strengthening reinforced concrete (RC) columns, particularly in seismic regions. However, there are many uncertainties concerning the behavior of the composite specimen, particularly at the interface between the old and new concrete. In this paper, monotonic finite element (FE) analyses are performed to examine the behavior of strengthened columns under monotonic and cyclic loading. Through investigating two independent series of experimental results, it is demonstrated that monotonic FE analysis with appropriate assumptions can simulate both monotonic and cyclic loading conditions to a reasonable degree of accuracy. According to the results of this study, it is found that a simulation of the interface between the old and the new concrete is vital and cannot be ignored by simply considering a perfect bond at the interface. In the case of strengthened RC columns subjected to cyclic loading, strength degradation at the interface has to be included and can be effectively modeled by reducing the coefficients of friction and adhesion by using a proposed formula. Finally, the effect of jacket concrete shrinkage is simulated that leads to a reduced maximum load and stiffness of strengthened columns. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Reconstruction of sub-wavelength fractures and physical properties of masonry media using full-waveform inversion of proximal penetrating radar   总被引：1，自引：0，他引：1  

Claudio Patriarca  Sbastien Lambot  M.R. Mahmoudzadeh  Julien Minet  Evert Slob 《Journal of Applied Geophysics》2011,74(1):26-37

  相似文献   

预制装配式剪力墙结构墙板节点抗震性能研究   总被引：2，自引：1，他引：1  

朱张峰  郭正兴 《地震工程与工程振动》2011,31(1):35-40

为掌握预制装配式剪力墙结构墙板节点的抗震性能,对2个现浇试件和2个预制装配式试件进行了拟静力试验.结合非线性分析手段,从承载能力、变形能力、受力机理以及破坏模式等方面综合分析了其抗震性能,并初步探讨了墙板连接钢筋的合理直径.分析结果表明:与现浇试件相比,预制装配式试件承载能力较高,位移延性系数相同,滞同环均较饱满,具有...  相似文献