河南某地热井管挤毁事故分析及处理          下载免费PDF全文

张秋冬  卢予北  吴青松  赵建粮 《探矿工程》2009,36(3):18-20

中原地区地热井成井中使用的过滤管大多为桥式过滤管,在下管过程中,如果泥浆性能不均匀或者管内灌浆不及时等,使得管内外压力不平衡,而当该压力超过过滤管的抗挤强度后就容易造成过滤管挤毁事故的发生。针对河南某地热井下管中发生的过滤管挤毁事故,分析造成该类事故的原因及在成井过程中应注意的问题。  相似文献   

5.12汶川地震崩塌滑坡分布特征及影响因子评价——以都江堰至汶川公路沿线为例   总被引：5，自引：2，他引：3  

庄建琦  崔鹏  葛永刚  朱颖彦  刘应辉  裴来政 《地质科技情报》2009,28(2)

以都江堰至汶川公路沿线为研究对象,利用遥感影像解译和野外调查数据,探讨了都汶公路沿线地震崩塌滑坡分布规律,并利用主成分分析,确定了影响地震崩塌滑坡的关键影响因子.结果表明:①地震崩塌滑坡主要分布在坡度为30～65°的坡体上,其崩塌滑坡面积占总面积的82.79%;坡向为东、东南和南坡3个坡向, 其崩塌滑坡面积占总面积的51.32%;其分布的坡面粗糙度多为Ⅰ~Ⅳ级,其崩塌滑坡面积占总面积的84.45%;集中在距主断层距离5～20 km范围内,其崩塌滑坡面积占总面积的56.15%;土地利用类型主要为有林地、灌木林地和疏林地,尤其是灌木林地,三者的崩塌滑坡面积占总面积的89.93%;地层岩性主要为第1、2、3和20类地层岩性组合,其崩塌滑坡面积占总面积的41.34%.②根据主成分分析,坡度和坡面粗糙度对地震崩塌滑坡的贡献最大,是影响地震崩塌滑坡的关键因子,其次是距主断层距离和土地利用,坡向和地层岩性对地震崩塌滑坡的贡献程度较小.  相似文献   

神府—东胜矿区采煤塌陷对包气带结构的影响     

ZHANG Fa-wang  张发旺  宋亚新  赵红梅  么红超  马彦超 《现代地质》2009,23(1)

通过对比采煤前和采煤塌陷过程中及稳定后包气带结构的变化,详细研究了神府—东胜矿区采煤塌陷对包气带结构的影响。研究结果表明:在采煤塌陷前,包气带组成岩性主要为风积砂岩和萨拉乌苏组粗砂岩,相对较薄,包气带组成介质层序较清晰,各岩性介质颗粒排列有序、均一,包气带内部结构以孔隙为主;在采煤发生后的塌陷非稳定阶段,塌陷裂隙贯通含水层,使地下水大量渗漏,同时产生大量贯穿地表的裂隙,引起岩土孔隙性发生变化,使得塌陷区包气带变厚,在一定深度上结构不均,浅部包气带结构转化为以裂隙为主;到塌陷稳定阶段,包气带结构变化趋于稳定,厚度增加,但在地表以下仍存在一些断续的裂缝(隙),使塌陷区包气带形成以孔隙为主,间夹断续裂隙的特殊包气带结构。  相似文献   

龙岩盆地岩溶的发育程度及塌陷易发性评价     

何道金 《福建地质》2009,28(4):326-334

通过对龙岩盆地岩溶塌陷易发区地质环境特征、发育程度和分布规律的总结对比,分析岩溶塌陷地质灾害成因,采用积分值法对潜在塌陷区域进行易发性评价。  相似文献   

改进的边折叠三角网简化优化算法研究     

张立朝  陈引川  余琳琳 《测绘科学》2006,31(6):54-55,53

本文提出了一种改进的“边折叠”模型三角网简化算法。该算法通过对误差变量的选择,建立了有效的边“折叠价值”计算公式对简化进行局部误差控制。算法很好地解决了约束型狄洛尼三角网中的数据冗余问题,提高了三维模型数据的传输速度和显示的实时性,最后利用单侧豪斯道夫距离给出了模型简化前后整体的误差变化。  相似文献   

Probabilistic analysis of three-dimensional tunnel face stability in soft rock masses using Hoek–Brown failure criterion     

Jiahua Zhang  Lianyang Zhang  Weijun Wang  Daobing Zhang  Biao Zhang 《国际地质力学数值与分析法杂志》2020,44(11):1601-1616

This paper investigates tunnel face stability in soft rock masses via coupled limit and reliability analyses. Specifically, a 3D face collapse mechanism was first constructed. Then the Hoek–Brown failure criterion was introduced into the limit analysis via the tangential technique. Taking the variability of rock mass parameters and loads into consideration, a reliability model was established. The collapse pressure and failure range of tunnel faces were determined. In addition, the required factor of safety (FS) and supporting pressure under three safety levels were obtained, and the corresponding safety level graphs for support design were presented. Comparison of the obtained results with previous work demonstrates the rationality of the 3D collapse mechanism and the validity of the results. A decrease in the geological strength index, Hoek–Brown parameter m_i, and uniaxial compressive strength or an increase in the disturbance factor results in a nonlinear increase of the collapse pressure and an enlargement of the failure zone. Such changes also lead to a nonlinear increase of the required support pressure under a certain safety level. By contrast, the FS does not exhibit any obvious change when these parameters vary. Therefore, when a rock mass is of poor quality or heavily disturbed, the advance support should be enlarged from upper front to right above the tunnel face. Moreover, as the safety level increases, both the required FS and supporting pressure of the tunnel face increase nonlinearly at a higher rate.  相似文献   

ENVIRONMENTAL GEOLOGY     

《Abstract of Chinese Geological Literature》2014,(2)

正20141205Cheng Weiming(State Key Laboratory of Resources and Environmental Information System,Institute of Geographic Sciences and Natural Resources Research,CAS,Beijing 100101,China);Xia Yao Regional Hazard Assessment of Disaster Environment for Debris Flows:Taking Jundu Mountain,Beijing as an  相似文献   

汶川Ms8．0地震驱动的同震及震后地质灾害空间分布   总被引：1，自引：0，他引：1  

颜照坤  李勇  黄润秋  李奋生  张自力  张威  闫亮  Robert G．Hilton 《四川地震》2011,(4):1-7

汶川大地震驱动了大量的同震崩塌、滑坡等地质灾害,这些地质灾害同时造成了山谷中大量的松散堆积物堆积,并将以泥石流的形式进入河流系统,造成震后大规模的泥石流地质灾害,这也是地震灾区在震后面临的最为严峻的问题。根据本项目组的卫星影像处理和实地观测工作,以及前人对同震地质灾害研究获得的数量资料,对同震地质灾害数量在平行于断裂方...  相似文献   

A new indicator of elastic spectral shape for the reliable selection of ground motion records     

Mehdi Mousavi  Mohsen Ghafory‐Ashtiany  Alireza Azarbakht 《地震工程与结构动力学》2011,40(12):1403-1416

How to select a limited number of ground motion records (GMRs) is an important challenge for the non‐linear analysis of structures. Since epsilon (ε_Sa) is an indicator of spectral shape, which has a significant correlation with the non‐linear response of a structure, the selection of GMRs based on the hazard‐related target ε_Sa is a reasonable approach. In this paper, an alternative indicator of spectral shape is proposed, which results in a more reliable prediction of the non‐linear response for the structures with the natural period of 0.25 to 3.0 s. This new parameter, named eta (η), is a linear combination of ε_Sa and the peak ground velocity epsilon (ε_PGV). It is shown that η, as a non‐linear response predictor, is remarkably more efficient than the well‐known and convenient parameter ε_Sa. The influence of η‐filtration in the collapse analysis of an eight‐story reinforced concrete structure with special moment‐resisting frames was studied. Statistical analysis of the results confirmed that the difference between ε‐filtration and η‐filtration can be very significant at some hazard levels. In the case of this structure, the resulting annual frequency of collapse was found to be lower in the case of η‐based record selection, in comparison with the ε‐based record‐selection approach. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

矿区岩溶地表塌陷神经网络预测研究   总被引：3，自引：0，他引：3  

罗周全  徐海  杨彪  王益伟 《中国地质灾害与防治学报》2011,22(3):39-44

针对近年来某矿岩溶地表塌陷频繁发生的现象,分析确定了影响地表塌陷的主要因素,构建了矿区岩溶地表塌陷预测BP神经网络模型,以训练后的BP网络模型对矿山帷幕注浆三期工程完成后可能形成的地表塌陷区的空间分布进行预测。并针对矿山现实塌陷情况,结合各区预测塌陷危险分级结果,提出了相应的岩溶地表塌陷灾害防治措施。实践表明,所建模型的预测结果与矿区地表塌陷实际情况相符,可为矿山后续帷幕注浆工程的设计与施工提供有益借鉴,为岩溶矿区地表塌陷灾害提供预警支持。  相似文献