共查询到19条相似文献,搜索用时 777 毫秒
1.
本文通过考虑地震烈度的随机性和模糊性,以及石结构强度破坏等级界限的模糊性,研究多层石结构抗震抗剪能力的可靠性问题.将地震地面运动模拟为含有模糊烈度参数的平稳过滤有色噪声的随机过程,引入抗剪强度破坏指数,建立了石结构抗震抗剪能力的模糊安全准则,为研究多层石结构的抗震抗剪能力可靠性提供了一个合理的评定方法。 相似文献
2.
3.
福建省地震局和福建省晋江地区地震办公室于1983年10月编辑了《石结构建筑物防震抗震科普画册》,已于1984年初出版。该画册为16开本,共约50页,图文并茂,印有110余幅图,其中彩色照片和水彩画约40幅、黑白照片约20幅、图画约70幅。该画册从房屋结构抗震的角度,较全面地收集介绍了古今各种石结构房屋和其他建筑物的资料,展现了1604年泉州海外8级大地震和1918年广东南沃7级强地震的历史背景。内容分为三个部份:第一部份是“古建筑”,包括:“经受8级大地震考验的宋代石结构建筑”,其中有余敏的“玄妙壮观的泉州东、西塔——兼议建筑结构抗震》,介绍安平桥、姑嫂塔、日湖塔和崇武古城等的“抗震史话”;还包括陈泗东、琴簧的《从震后重修重建的部份石结构古建筑看古代劳动人 相似文献
4.
具有悠久历史的石结构是砌体结构的重要组成部分,本文作者经广泛调研和试验分析:(1)提出以石粉为集料对石砌体进行抗震加固,寓环保与防灾于一体;(2)给出新型浆体配比和复合砂浆的强度等级,阐述加固技术和方法,建立灌浆石砌体抗震抗剪强度公式;(3)阐明抗震验算方法,提出基于模糊随机可靠理论的可靠性分析方法。 相似文献
5.
6.
7.
根据抗震设计规范要求,结构工程具体实际情况,从结构的选型,构件断面的确定等几方面进行了简述,为提高结构整体抗震性能,在设计中采取了有效的抗震借鉴。 相似文献
8.
通过建立框架-抗震墙结构单元模型,采用在楼层处有集中力而在楼层之间有分布力的地震作用模式并考虑抗震墙剪切变形的影响,得到了结构内力和变形之间的公式。根据实例分析可得抗震墙剪切变形对整体结构变形影响很小,因此一般情况下在计算框架-抗震墙结构时忽略剪切变形是合理的;同时发现框架剪切刚度越大,抗震墙剪切变形对框架-抗震墙结构整体变形的影响就越大,反之则越小。 相似文献
9.
10.
为评估大跨度上承式钢管混凝土(Concrete-filled Steel Tube, CFST)拱桥在不同地震动强度下的抗震韧性,以一座320 m上承式CFST拱桥为研究对象,利用Midas/Civil软件建立结构有限元模型并进行非线性结构响应分析,定义了拱桥的易损性组和性能组,开展地震易损性分析,分别评估在不同地震动强度作用下拱桥结构的维修费用和维修时间等抗震韧性指标,给出拱桥的抗震韧性评级方法和依据。结果表明:该结构最终抗震韧性评级为一星,其中维修时间是影响拱桥结构综合抗震韧性等级的关键指标,结构构件对拱桥结构的抗震韧性有较大的影响。 相似文献
11.
鉴于格宾石笼护岸、护坡等优质特性,对其应用至地震减灾工程进行研究。经分析可知,格宾石笼主要利用双绞合六边形金属网片组合为箱笼,再装填石料堆筑构成防护整体;格宾石笼具有高强度耐久性、透水性、整体性与柔韧性和施工过程简单便利等特征。依据格宾石笼构造与特性分析,分别将地震减灾工程下格宾石笼拦挡坝施工划分为格宾石笼护基与格宾石笼护坡两部分进行研究。利用测量放线、挖掘基础、规整地基、铺垫反滤层、格宾放置与连接、支顶加固、石料装填封盖等步骤实现格宾石笼护基施工。通过削坡、铺设土工布、砂砾垫层、安装网箱、装填石料和封盖等步骤实现格宾石笼护坡施工。分别在冲击力、位移和能量三方面验证格宾石笼拦挡坝支护技术,实验结果表明,冲击力和坝体自身材料性质有关联,格宾拦挡坝材料属于柔性材料,冲击力由此减小,耗费冲击力能量效果十分明显;坝体可以利用整个结构全部能量承担很大负载;格宾石笼拦挡坝体耗能效果显然优于浆砌石坝。 相似文献
12.
13.
D. L. Dunkerley 《地球表面变化过程与地形》1995,20(3):207-218
Surface stones are a common feature of desert hillslopes. They influence slope processes ranging from the interception and partitioning of rainwater to the dislodgement and transport of regolith particles. The aspects of a stone mantle which relate to these various influences are diverse, and include surface cover fraction, dimensions of the infiltration annulus, and geometric and packing effects. Analyses of the characteristics of stone cover at two study sites were made using photographic methods and are used to evaluate different means of reporting mean stone sizes. It is found that mean diameter based on weight, as conventionally employed in sieve analysis, is insensitive to important stone cover characteristics and may be influenced greatly by uncommon, large stones. Similarly, mean diameters based on count become inappropriate if large numbers of small stones dominate the calculated mean, concealing other site-to-site differences in stone cover. As a more appropriate parameterization of stone geometry, the use of mean diameters weighted by stone surface area and perimeter length are proposed. These weighting factors have the advantage that they relate closely to stone characteristics relevant to slope hydrology and erosion processes. 相似文献
14.
《中国科学:地球科学(英文版)》2017,(3)
In this paper we report on Longgudong,an Early Pleistocene cave site in south China which was systematically excavated in 1999 and 2000,and where human teeth and associated stone artifacts were discovered within the same stratigraphic layer.The age of this site was estimated from faunal comparisons and palaeomagnetism and has been attributed to the Early Pleistocene,most probably the earlier Early Pleistocene.The human teeth from this site have been well studied.However,the stone artifacts are still unknown to most scholars.This paper thus presents an analysis of the lithics as the first firmly demonstrated stone tools associated with Early Pleistocene human fossils in south China. 相似文献
15.
Throughout history, dry-stone masonry structures have been strengthened with different types of metal connectors in order to increase their resistance which enabled their survival, especially in the seismically active area. One such example is the ancient Protiron monument placed in the Peristyle square of the Diocletian's Palace in Split, Croatia. The Protiron was built at the turn of the 3rd century as a stone masonry structure with dowels embedded between its base, columns, capitals and broad gable. The stone blocks in the broad gable were connected by metal clamps during restoration at the beginning of the 20th century. In order to study the seismic performance of the strengthened stone masonry structures, an experimental investigation of seismic behaviour of a physical model of the Protiron was performed on the shaking table. The model was designed as a true replica model in a length scale of 1:4 and exposed to representative earthquake with increasing intensities up to collapse. The tests provided a clear insight into system behaviour, damage mechanism and failure under intensive seismic load, especially into the efficiency of connecting elements, which had a special role in increasing seismic resistance and protection of the structure from collapse. Additionally, this experiment provided valuable data for verification and calibration of numerical models for strengthened stone masonry structures. 相似文献
16.
为保护地震作用下历史遗迹帕特农神庙多鼓石柱,提出将破损的石鼓替换为填充颗粒的空鼓,以减轻多鼓石柱动力响应。本文基于PFC3D与FLAC3D软件,实现了离散-有限耦合作用,模拟了附有颗粒阻尼器帕特农神庙多鼓型石柱,研究了颗粒阻尼器对帕特农神庙石柱的减震效果,并分析地震强度、频率、阻尼器位置等因素对减震效果的影响。研究结果表明,将颗粒阻尼器替换破损的空鼓,PFC3D与FLAC3D耦合计算结果与试验结果基本一致,减震效果显著,说明耦合分析方法研究颗粒阻尼器抗震性能具有较高的可靠性;地震强度不同时,分层颗粒阻尼器仍可较好地耗散能量;颗粒阻尼器对结构的减震性能受激励频率的影响显著,频率越高,减震效果越好;颗粒阻尼器布置在古柱中上部减震效果优于布置在古柱下部。 相似文献
17.
长期研究表明,寿山石的成矿地质条件主要受地层、构造、火山机构和火山成矿等综合作用控制。寿山石的矿物成分主要为地开石、高岭石和叶蜡石。因寿山石的成矿地质条件、矿物组成和产出部位的不同,形成色彩绚丽、命名异样、品种繁多、分类殊异。但通常以其成因、产状和历史传统分为田坑石、山坑石和水坑石三类。为便于识别、研究和讨论,将寿山石的主要品种及其特征一并简介。 相似文献
18.
Giulio Castori Marco Corradi Alessandro De Maria Romina Sisti Antonio Borri 《Bulletin of Earthquake Engineering》2018,16(10):4561-4580
Studies oriented to restoration and conservation of historical monumental buildings have recourse to structural analysis as a way to investigate the genuine structural features of the construction, to better understand its present condition and actual causes of existing damage, to estimate its safety conditions and to determine necessary remedial measures. Based on this background, this paper discusses on the seismic vulnerability of masonry fortresses by means of an analysis methodology based on three different analytical procedures, according to an increased knowledge of the structure. As a relevant case study the Albornoz fortress, a 14th stone masonry construction located in central Italy, was selected. Initially, the strategy proposed to perform this task was aimed at testing and developing an expeditious and non-destructive procedure to evaluate both the seismic vulnerability and the main mechanical properties of the different masonry typologies. The macroscale structural behavior of the fortress was then evaluated through a nonlinear static analysis (pushover) and a more simple approach based on the kinematic theorems of the limit analysis. From this point of view, by comparing the capacity of the construction to withstand lateral loads with the expected demands resulting from seismic actions, these methods provided a highly effective means of verifying the safety of the masonry structure and its vulnerability to extensive damage and collapse. 相似文献
19.
石砌体结构抗震抗剪强度理论的应用 总被引:10,自引:0,他引:10
本文基于石砌墙体的拟动力实验、工程实践及震害经验,经分析研究,提出石砌体结构的抗震设计强度验算及抗震设计方法,并结合实际工程计算,验证了本研究的可靠性与实用性。 相似文献