底层大空间带暗支撑剪力墙结构非线性地震反应分析   总被引：4，自引：0，他引：4  

张建伟  曹万林  孙继强  张振钢 《世界地震工程》2003,19(3):91-96

利用在剪力墙多垂直杆非线性单元模型中增设支撑斜杆的方法，来分析带暗支撑剪力墙结构的非线性地震反应，给出了带支撑斜杆的多垂直杆剪力墙单元模型的刚度矩阵和各元件的本构关系。最后提供了算例，并与试验结果比较，表明带支撑斜杆的多垂直杆剪力墙非线性单元模型具有较好的计算精度。  相似文献   

配筋砌体结构地震易损性评价方法初探   总被引：5，自引：0，他引：5  

于德湖  王焕定 《地震工程与工程振动》2002,22(4):97-101

本文首先简要介绍了考虑空间协同的配筋砌体结构弹塑性地震反应分析程序EDAPSC；然后提出了一种利用空间协同时程分析结果，对配筋砌体结构地震易损性进行定量评价的方法，并以上海园南小区住宅楼为例进行了地震易损性分析，说明本文提出的地震易损性评价方法是可行和合理的；另外作者还对设计人员提出了提高结构抗震安全性的建议。  相似文献   

纤维塑料约束混凝土柱抗震性能研究综述   总被引：14，自引：1，他引：14  

于清  陶忠 《地震工程与工程振动》2002,22(2):66-72

作为一种新型建筑结构材料，纤维塑料（Fiber Reinforced plastic,简称FRP）在某些特定的条件下可替代传统的木、钢和钢筋材料，具有高强、轻质、抗腐蚀和耐疲劳，温度作用下稳定性好等特点，因而受到土木工程界的关注。本文简要从结构试验、计算理论和计算方法三个方面阐述了国内外研究者对FRP约束混凝土抗震性能的研究现状，并分析了研究中存在的不足。在比较了大量的研究成果之后，基于组成FRP约束混凝土的FRP及其核心混凝土之间组合作用的特点，探讨了FRP约束混凝土抗震性能研究中的若干关键问题。最后，展望了FRP约束混凝土结构抗震性能研究的发展前景。  相似文献   

Effect of masonry infills on seismic performance of a 3‐storey R/C frame with non‐seismic detailing     

Han‐Seon Lee  Sung‐Woo Woo 《地震工程与结构动力学》2002,31(2):353-378

The objective of this study is to investigate the effect of masonry infills on the seismic performance of low‐rise reinforced concrete (RC) frames with non‐seismic detailing. For this purpose, a 2‐bay 3‐storey masonry‐infilled RC frame was selected and a 1 : 5 scale model was constructed according to the Korean practice of non‐seismic detailing and the similitude law. Then, a series of earthquake simulation tests and a pushover test were performed on this model. When the results of these tests are compared with those in the case of the bare frame, it can be recognized that the masonry infills contribute to the large increase in the stiffness and strength of the global structure whereas they also accompany the increase of earthquake inertia forces. The failure mode of the masonry‐infilled frame was that of shear failure due to the bed‐joint sliding of the masonry infills while that of the bare frame appeared to be the soft‐storey plastic mechanism at the first storey. However, it is judged that the masonry infills can be beneficial to the seismic performance of the structure since the amount of the increase in strength appears to be greater than that in the induced earthquake inertia forces while the deformation capacity of the global structure remains almost the same regardless of the presence of the masonry infills. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   

A new modelling strategy for the behaviour of shear walls under dynamic loading     

J. Mazars  P. Kotronis  L. Davenne 《地震工程与结构动力学》2002,31(4):937-954

A new simplified modelling strategy to simulate the non‐linear behaviour of reinforced concrete shear walls under dynamic loading is presented. The equivalent reinforced concrete (ERC) model is derived from the framework method and uses lattice meshes for concrete and reinforcement bars and uniaxial constitutive laws based on continuum damage mechanics and plasticity. Results show the capacity of the model to analyse structures having different slenderness and boundary conditions. For low reinforcement ratios however, results are sensitive to the angle formed by the diagonals of the concrete lattice and the horizontal bars. The method is compared with the shear multi‐layered beam model that uses Timoshenko multi‐layered 2D beam elements and biaxial constitutive laws. Comparisons for both models with experimental results of two research programs (one organized by NUPEC and the other by COGEMA and EDF) are provided. ERC is a simplified method that intends to save computer time and allows parametrical studies. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

崇州市某水电站引水隧洞砼腐蚀原因分析及防治建议   总被引：1，自引：0，他引：1  

盛东劲  霍加庆 《四川地质学报》2003,23(1):23-25

对四川省崇州市某水电站引水隧洞衬砌砼产生腐蚀变质的原因进行了分析，指出环境水对砼的结晶性侵蚀是最根本和直接的因素。在水电站勘察设计阶段，未对地质环境尤其是水文地质及地下水下水化学性质进行评价，故而在工程设计方案中，对砼的主要原材料水泥的标号及成份要求未考虑环境水对砼的侵蚀问题，本文对此提出了相应了防治建议。  相似文献   

东海大桥主墩大直径钻孔灌注桩钻头设计          下载免费PDF全文

王文明  吴初兴 《探矿工程》2004,31(12):30-32

针对钻头包泥堵钻和钙质胶结层难以进尺等影响钻进效率的几个问题，对刮刀钻头结构进行了改进设计，并取得了令人满意的效果。  相似文献   

现浇混凝土薄壁管桩内摩阻力的数值分析   总被引：2，自引：0，他引：2  

刘汉龙  费康  周云东  高玉峰 《岩土力学》2004,25(Z2):211-216

现浇混凝土薄壁管桩(简称PCC桩)技术是河海大学自主开发研制的用于地基加固处理的新技术,它是一种适合于软土地区的新型高效优质桩型.在全面介绍了PCC桩非线性有限元分析模型的建立过程后,对PCC桩的内摩阻力进行了计算分析.分析结果表明,土塞底部的水平应力在荷载作用过程中有较大的提高,相应位置的内摩阻力达到极限值,内摩阻力沿土塞呈指数曲线分布.同时,对内摩阻力分布规律的主要因素影响也进行了分析,给出了相应的简化计算公式.  相似文献   

Factors affecting the groundwater chemistry in a highly urbanized coastal area in Hong Kong: an example from the Mid-Levels area   总被引：1，自引：0，他引：1  

Chi-man Leung  Jiu J. Jiao  John Malpas  Wing-tat Chan  Yan-xin Wang 《Environmental Geology》2005,48(4-5):480-495

Coastal areas of Hong Kong Island are one of the most extensively urbanized areas in the world. Groundwater samples in natural slopes and developed spaces in the regions centered by the Mid-Levels area, Hong Kong Island, were collected and analyzed to investigate the natural and anthropogenic processes affecting the groundwater chemistry. The results presented may be of value to other coastal areas in the world for the identification of possible groundwater contamination sources. Groundwater samples in the natural slopes were in low total dissolved solid (TDS) (<100 mg/l), indicating that the waters were in the early evolutionary stage. Using chloride as a normalizing factor, the “non-marine” components of different major ions in the samples were calculated. The correlation analysis indicated the occurrence of weathering of plagioclase feldspars in the natural slopes. However, the breakdown of biotite and K-feldspar seems to be limited by short groundwater residence time and high resistance to weathering. The high variety in hydrochemical facies may suggest the presence of extremely heterogeneous subsurface geological conditions. In the developed spaces, groundwater samples exhibited a high range of TDS (~100–5300 mg/l) and were mainly dominated by Na–Cl and Na–Ca–Cl water types. Besides water-rock interactions, the groundwater chemistry was significantly affected by leakage from service pipes and the dissolution of concrete materials. Some chemicals were used as signatures to identify the leakage from various service pipes. The area generally suffered from widespread, but small amount of leakages, and no obvious leakage was discovered. The strong correlations among major cations and chloride suggested that even a small amount of leakage from salty flushing water pipes can significantly affect the groundwater chemistry. Groundwater is found to be highly aggressive toward concrete as supported by three commonly used aggressiveness indices. Additional Ca²⁺ may be released to groundwater by corrosion of subsurface concrete materials such as building foundations and basements. The strength of those subsurface engineering structures may be weakened. Besides, excess Ca²⁺ may deposit in the dewatering systems in the area, which may affect their performance in lowering high water tables. The findings regarding leakage from service pipes will be useful for various government organizations such as the Water Supplies Department and Drainage Services Department. Discussion of the behavior of Ca²⁺ is instructional to foundation and slope dewatering designs in the area.  相似文献   

Nonlinear Stability Analysis of Long-Span Continuous Rigid Frame Bridge with Thin-Wall High Piers     

LiLi PengYuancheng LongXiaohong LiaoPing 《中国地质大学学报(英文版)》2005,16(1):72-78

By utilizing the current finite element program ANSYS, two types of finite element models (FEM), the beam model (BM) and shell model (SM), are established for the nonlinear stability analysis of a practical rigid frame bridge-Longtanhe Great Bridge. In these analyses, geometrical and material nonlinearities are simultaneously taken into account. For geometrical nonlinearity, updated LagrangJan formulations are adopted to derive the tangent stiffness matrix. In order to simulate the nonlinear behavior of the plastic hinge of the piers, the multi-lines spring element COMBIN39 is used in the SM while the bilinear rotational spring element COMBIN40 is employed in the BM. Numerical calculations show that satisfying results can be obtained in the stability analysis of the bridge when the double coupling nonlinearity effects are considered. In addition, the conclusion is significant for practical engineering.  相似文献