一次强雷击空气冲击波引发灾害过程分析   总被引：1，自引：0，他引：1  

赵贤产  吴剑强  马宁  黄嵘 《气象科技》2012,40(6):1025-1029

对2010年9月13日发生在浙江省义乌城区附近室内隔墙倒塌事件,从雷暴和雷电强度、空气冲击波原理、隔墙墙体的牢固度等方面进行详细分析.结果表明室内的隔墙未作有效加固处理,是隔墙倒塌的内因;当天的10级大风所产生的风压,对隔墙倒塌具有一定影响,但雷暴云团强度强,雷电的负闪电流强度达到416.798 kA,远远超过一般雷灾强度100～200 kA的值,在近距离的雷电放电造成的空气冲击波,对隔墙倒塌具有引发作用是主要因素.  相似文献   

Discovery of an optical flare from GRB 060926 by the MASTER robotic telescope: Possible formation of a marginally rotating black hole     

V. M. Lipunov  V. G. Kornilov  E. S. Gorbovskoy  A. V. Krylov  N. V. Tyurina  D. A. Kuvshinov  A. A. Belinski  P. A. Gritsyk  A. V. Sankovich  V. V. Vladimirov 《Astronomy Letters》2008,34(3):145-151

The MASTER robotic telescope has obtained the first optical images of GRB 060926. We have discovered an optical flare from GRB 060926, a recurrent brightening that closely follows its behavior in the X-ray range. We have determined the spectral slope for GRB 060926 from the X-ray to optical range in the first minutes. Based on the spinar model, we show that the parameters of the optical and X-ray flares suggest that the gamma-ray burst resulted from the core collapse of a 7M _⊙ star with an initial effective Kerr parameter of 7.6 and an initial magnetic-to-gravitational energy ratio of 10^?4.  相似文献   

Seismic loss estimation of non‐ductile reinforced concrete buildings     

M. Baradaran Shoraka  T. Y. Yang  K. J. Elwood 《地震工程与结构动力学》2013,42(2):297-310

Non‐ductile reinforced concrete buildings represent a prevalent construction type found in many parts of the world. Due to the seismic vulnerability of such buildings, in areas of high seismic activity non‐ductile reinforced concrete buildings pose a significant threat to the safety of the occupants and damage to such structures can result in large financial losses. This paper introduces advanced analytical models that can be used to simulate the nonlinear dynamic response of these structural systems, including collapse. The state‐of‐the‐art loss simulation procedure developed for new buildings is extended to estimate the expected losses of existing non‐ductile concrete buildings considering their vulnerability to collapse. Three criteria for collapse, namely first component failure, side‐sway collapse, and gravity‐load collapse, are considered in determining the probability of collapse and the assessment of financial losses. A detailed example is presented using a seven‐story non‐ductile reinforced concrete frame building located in the Los Angeles, California. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

An efficient method for estimating the collapse risk of structures in seismic regions   总被引：1，自引：0，他引：1  

Laura Eads  Eduardo Miranda  Helmut Krawinkler  Dimitrios G. Lignos 《地震工程与结构动力学》2013,42(1):25-41

Assessing the probability of collapse is a computationally demanding component of performance‐based earthquake engineering. This paper examines various aspects involved in the computation of the mean annual frequency of collapse (λ_c) and proposes an efficient method for estimating the sidesway collapse risk of structures in seismic regions. By deaggregating the mean annual frequency of collapse, it is shown that the mean annual frequency of collapse is typically dominated by earthquake ground motion intensities corresponding to the lower half of the collapse fragility curve. Uncertainty in the collapse fragility curve and mean annual frequency of collapse as a function of the number of ground motions used in calculations is also quantified, and it is shown that using a small number of ground motions can lead to unreliable estimates of a structure's collapse risk. The proposed method is shown to significantly reduce the computational effort and uncertainty in the estimate. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

近地表上覆岩层直壁塌陷机理及稳定性分析     

李庶林  王伟  林建宁 《中国地质灾害与防治学报》2012,23(2):44-49

介绍了川口钨矿塌陷区岩层的地质条件、岩石的力学性质和工程地质调查与评价的结果;通过井下和地表现场调查和勘察测定,给出了井下采空区的边界范围和地表塌陷范围的对照图,分析了上覆岩层的塌陷特点,确定了采空区上覆岩层呈现典型的筒状直壁塌陷。根据采空区围岩和上覆岩层的节理裂隙发育程度不同,采用太沙基地压理论解释了采空区周边围岩和上覆岩层的力学作用机理和破坏特点,对太沙基理论进行了改进,并给出了力学分析图、推导了地压计算公式;进而采用极限破坏理论对不同开采跨度时上覆岩层的稳定性进行了分析和计算,并给出了在保证不产生筒形塌陷条件下、不同覆盖层厚度时的安全开采跨度和安全系数之间的量化关系。  相似文献   

苏州小茅山矿山采空区勘查研究与应用          下载免费PDF全文

赵金勇 《江苏地质》2012,36(4):434-438

采空塌陷是地下开采矿山主要的地质灾害之一,矿山关闭后采空区土地资源如何开发利用至关重要。以苏州小茅山矿山采空区勘查研究与应用为实例,从采空区的地质环境条件特征分析入手,采用系统搜集资料,实地地质测绘,地球物理勘探验证,综合研究分析评价的"四步骤"方法,对采空区场地土地适宜性进行了评价。  相似文献   

Relating rapid plate-motion variations to plate-boundary forces in global coupled models of the mantle/lithosphere system: Effects of topography and friction     

Giampiero Iaffaldano  Hans-Peter Bunge 《Tectonophysics》2009,474(1-2):393

Recent high-resolution models of past plate motions and their comparison with plate motion models inferred from space geodetic techniques reveal a number of short-term variations in global plate velocities over the past 10 Myrs. Such variations serve as powerful probe into the nature and magnitude of plate boundary forces, because they are unlikely to originate from changes in mantle buoyancy forces, which evolve on longer time scales. Here we explore the constraints of the velocity record using a novel coupled modeling-approach of global neo-tectonic simulations combined with realistic plate driving forces obtained from mantle circulation models (MCMs) to arrive at simple global budgets of mantle, lithosphere and plate boundary forces. We focus on three plate boundary systems along the Nazca/South America plate margin, the Aleutian trench and the India/Australia plate boundary to show that gravitational spreading from high topography in the Andes and Tibet contributes substantially to the global plate tectonic force balance and that this contribution is sufficient to explain some 35% of recent velocity changes over the Earth's surface, including among others the observed 30% convergence reduction between the Nazca/South America plates. Our models make a number of specific predictions such as significant lateral variations in plate coupling forces along a given margin revealed by trench-parallel gravity and bathymetry anomalies and the occurrence of large earthquakes, as well as differences by as much as a factor of five from margin to margin. They also support the notion of a relatively young plate boundary separating the India and Australia plates, which has been previously suggested based on independent observations. Importantly, we find that the modeled Nazca/South America convergence reduction explains recent spreading-rate variations in the South Atlantic and South Pacific, which points to the importance of far field effects on the adjacent continents in explaining the spreading record of oceanic basins. Our numerical results demonstrate (a) that detailed budgets of forces acting upon plates can be obtained and (b) support the notion of strong forcing along weak plate boundaries.  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   

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