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砂土液化判别和评价综合方法研究 总被引：22，自引：1，他引：22
在汇总分析已有领域知识和笔者们研究成果的基础上，建立了一套比较系统的地震液化和评价综合方法，包括初判条件，液化判别、液化危害性分析和抗液化措施等内容。 相似文献
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循环剪切吸水条件下饱和砂土的应力应变规律 总被引：1，自引：0，他引：1
在实际土工抗震边值问题中,饱和砂土在许多情况下并非处于完全不排水条件,可能由于土性等因素的不同而出现各异的排渗条件。排水条件对土体的动力应力应变响应有较大影响,本文基于新开发的孔隙水注入控制系统,进行了循环剪切条件下饱和砂土吸水试验,研究了剪切吸水对土体动力特性的影响规律。通过试验发现:剪切吸水条件下砂土的抗液化强度较不排水条件下降低,同样的循环剪切条件下轴向应变发展更大;试样的抗液化强度降低和轴向应变增加程度随剪切吸水率的增大而增加。基于对饱和砂土体变规律的已有研究,本文初步解释了剪切吸水条件下饱和砂土应力应变特性规律的物理实质。 相似文献
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砂土地震液化后大位移室内试验研究探讨 总被引：2，自引：0，他引：2
砂土地震液化引起的地面大位移会对结构产生灾难性的破坏，这已引起了人们的重视，但对其进行研究时间较短。作者在大量阅读有关资料的基础上，详细介绍了液化后地面大位移研究的室内试验设备、试验方法、试样的制备、试验的主要规律及国内的研究现状，并对试验技术和结果进行了探讨，指出以室内试验为基础提出液化后的本构模型及实用计算方法是今后工作的重点。 相似文献
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液化地基自由场振动台模型试验研究 总被引：4，自引：0，他引：4
进行了液化场地自由场振动台试验,试验采用柔性容器以减小边界影响,采用上覆黏土层的饱和砂土作为模型土。试验中再现了液化场地土的震害现象。得出的主要规律有:随着振次的增加,地基的频率迅速降低,阻尼比迅速增大;砂土对地震动起滤波作用;土体的加速度峰值反应在高度上呈"K"形分布;当最初加速度峰值到达前,砂土层中的孔压比存在负值;震后土中振动孔隙水压力不一定随振动的停止而立即开始消散,在短期内可能继续增长。 相似文献
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为了拓展海洋资源的开发与利用,近年来我国海洋人工岛屿的建设发展迅速。考虑到所处海域的地震风险与已有震害造成的严重破坏,既有与在建人工岛结构的地震风险不容忽视。针对人工岛结构抗震研究的2个主要问题,砂土液化灾害与结构动力稳定性问题,研究系统地回顾与总结了现有人工岛屿的建设方法、地震灾害以及抗震研究的现状等。并且,在梳理了目前研究的方法与工程问题后,提出了海洋人工岛抗震性能研究中仍存在的问题与研究重点。 相似文献
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降雨对深井水位动态的影响 总被引：4，自引：1，他引：4
本文根据我国地震地下水动态观测网中降雨对深井水位动态影响状况的普查与在北京、福建汤坑与黑龙江尚志等三个典型地区的现场观测试验的结果,讨论了降雨对深井水位年动态影响的类型、特征与模型及其影响因素、机理等,并依此探讨了我国震例中与降雨有关的三种异常的判据与信度问题。 相似文献
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地震成因是一个极复杂的问题,多学科的协作可能有助于对地震成因的探讨。本着这种想法,作者根据廿世纪七十年代发展起来的非平衡态统计物理学的理论基础,试图从“局域”模型出发探讨地震成因。 相似文献
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为国家工業建設地点提供地震参考資料,和全国地震危險地区的划分,是中国科学院地球物理研究所解放以来重点工作之一,承各方面的协助,笔者和徐煜坚等九人在苏联顧問帮助下編成了我国的“全国地震区域划分圖”。現在提出,作簡单的說明,請讀者提意見,以便作进一步的修正。 相似文献
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依据大地测量资料，分析研究了南口－孙河断层的活动性及其对区域构造活动的控制作用。研究认为，南口－孙河断层现今仍有活动，东三旗以西为张性反扭。该断层对首都圈构造活动具有控制作用，为一主干断层，近期活动增强。在首都圈构造活动性研究及地震趋势预测中，对南口－孙河断层必须予以足够的重视 相似文献
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柯坪塔格前缘断裂东段是柯坪推覆构造系前缘的一条活动断裂,野外调查获得了其晚第四纪错断洪积扇、冲沟阶地面的证据,实测了变形地貌面上的断层陡坎,分析了断层的形变量,通过采样测年估算了断层的缩短速率。由7个观测点的断层陡坎剖面测量,计算了观测点处断层的水平缩短速率,结果表明,断裂弧顶部位的五道班、三间房以西及其大山口道班附近,断层错断了Ⅰ级和Ⅱ级洪积扇(阶地)。断层在这些地点最新活动强烈,水平缩短平均速率全新世以来为0·35~0·44mm/a,更新世晚期末以来为0·16~0·30mm/a,而在非弧顶部位的巴楚磷矿、三岔口以北及大山口北断层只错断了更新世晚期Ⅲ级洪积扇,且水平缩短速率较小,断层水平缩短平均速率更新世晚期以来为0·05~0·07mm/a 相似文献
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W. DOMZALSKI 《Geophysical Prospecting》1966,14(3):273-291
The term “structure”, as used here, includes synclinal and anticlinal folds and folding in general, faults, cross fractures and various conditions associated with intrusions. Structure, both regional and local, has a very important role in emplacement of mineralization. Under certain circumstances which occur fairly commonly, structural conditions are reflected significantly in the trends and intensities apparent on aeromagnetic maps. A number of documented illustrations based on Canadian Shield conditions are discussed. Illustrations are drawn from areas of known geology and from proven mining camps, as well as from loci of recent discoveries. Canadian examples are chosen because of existence and availability of extensive aeromagnetic cover, although it is logical to extend the argument to other shields and indeed to regions of other geological, but similar magnetic character. The importance of aeromagnetics in structural approach to exploration and the correctness of such approach seem to be fully substantiated by results discussed. 相似文献
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EXPERIMENTAL STUDY OF TEMPERATURE EVOLUTION AND IDENTIFICATION OF INSTABILITY POSITION OF PLANAR STRIKE-SLIP FAULT DURING PROCESS OF STICK-SLIP 
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下载免费PDF全文 Stick-slip of fault in laboratory accompanies change of temperature. Temperature change is not only concerned with sliding friction, but also with the stress state of the sample. In this article, we use infra-red thermal imaging system as wide-range observation means to study the temperature variation of different stages during the deformation of sample. The rock sample for the experiment is made of granodiorite from Fangshan County with a size of 300mm×300mm×50mm. It is cut obliquely at an angle of 45°, forming a planar fault. Two-direction servo-control system was used to apply load on the sample. The load in both directions was forced to 5MPa and maintained constant (5MPa) in the X direction, then the load in the Y direction was applied by a displacement rate of 0.5μm/s, 0.1μm/s and 0.05μm/s successively. The left and below lateral of the sample were fixed, and the right and top lateral of the sample were slidable when loaded. The experiment results show not only the temperature change from increase to decrease caused by conversion of stress accumulation to relaxation before and after the peak stress, but also opposite variation of temperature increase on fault and temperature decrease in rock during instability stage. Most important of all, we have found the temperature precursor identifying the position of instability through the temperature variation with time along the fault. It shows that rate of temperature increase of instability position keeps relative high value since the stage of strongly off-linear stage, and accelerates in stage of meta-instability. After separating the effect of friction and stress, we found that temperature increase occurs in the rock near the fault instead of on the fault, which means the mechanism of temperature increase is stress accumulation. Temperature of fault at the instability position does not increase, which means the position is locked. We speculate that the position of locked area on fault with high stress accumulation near the fault may be the future instability position. It is of significance of studying temperature variation during stick-slip to the monitoring of earthquake precursors. Heat caused by friction of earthquake needs long time to transfer to the surface and could not be detected as a precursor. While the stress of surface rock near the fault would change as the stress of interior rock changes, which could cause detectable temperature variations. The research purpose of this article is to find special change positions before instability. As the temperature variations are caused by stress and slip of fault, the results are also meaningful to analysis of stress and displacement data related to earthquake precursors. 相似文献