溪洛渡和向家坝电站水库蓄水后对乐山市中南部地震活动的影响及对策

分析了乐山市中南部地震地质构造背景和历史地震活动特征，探讨了溪洛渡和向家坝电站水库蓄水后，这一地区断层活动及地震发展趋势，为尽力减轻地震灾害损失提出了相应的对策。     

第十一章 诱发地震对策

由于人类的工程活动引起地壳表层岩体失稳而产生的地震,称为诱发地震,如水库地震、抽液-注水地震、矿山地震等。一般来说,这种地震的震源很浅,烈度偏高,而且又多集中发生在重大工程设施和工矿企业地区,常给国民经济造成巨大的损失,因此越来越引起人们的重视。诱发地震是一个新的研究课题,目前以积累典型震侧,现场考察及观测研究为主,而对诱发地震对策的研究尚处于起步阶段。本章概要地介绍了水库地震、抽液-注液地震及矿山地震的危害及其可能的形成原因,进而论述了应付这些诱发地震的各项对策。     

利用水库诱发地震数据库快速为政府部门提供汶川M_s8.0地震灾害对策

根据水库诱发地震的发震相关因素和特点,确定出水库诱发地震数据库元参数和库结构,并通过资料收集初步建立起水库诱发地震数据库,它包含了全世界水库诱发地震震例1 31个、中国大Ⅰ型水库110座、中国大Ⅱ型水库200座和坝高达100m的水库70座,并具有快速查询、统计、图示等简单功能。在汶川M_S8.0地震发生后的第2天,应地震主管部门的要求及时给出了四川省及附近区域已建大型水库的基本信息及分布。可见,水库诱发地震数据库是有助于政府部门进行地震快速对策的一种有效工具     

乐山市盐气资源开发中应重视的一些问题

总结乐山市开发利用威西岩盐矿和犍为县麻柳场天然气出现诱发地震活动的特点,分析其形成原因,提出在威西岩盐矿和天然气开发区建立高质量的地震监测台网,为科学研究提供更多系统可靠的基础观测资料,深入开展盐气资源开发与诱发地震活动关系的研究,为制定科学合理的开发规划提供依据;开展跨行业科学研究,搞好盐气资源综合开发利用;切实抓好重大建设项目的抗震设防管理和各类设备的抗震安全,提高抗震防灾能力,加强领导与协调,共同做好盐气资源的开发利用。     

舟坝水电站水库蓄水对乐山市地震活动的影响及对策

在对铜街子水电站蓄水后库坝区及附近出现的地震活动特点进行分析的基础上,对另外一个舟坝水电站库坝区的地质结构和历史地震活动情况进行探讨,认为舟坝水电站蓄水产生诱发地震的可能性较大,五渡—利店断裂附近的马边、沐川、沙湾等地的诱发地震可能为5级以上,犍为县城附近可能出现的地震为4级左右。针对这些问题提出了减轻诱发地震造成损失的相应对策。     

识别地震谣传 减轻人为灾害

本文讨论了地震谣传与地震误传的内涵及其相互关系;研究了地震谣传的传播机理、放大畸变作用和对社会的严重危害;对地震谣传产生的背景,诱发地震谣传的主要因素及四川地震谣传的地区性特点等进行了讨论;并提出了识别、平息和预防地震谣传、减轻人为灾害的主要对策.     

应对汶川特大地震波及乐山事件的做法及思考

2008年5月12日汶川8.0级地震是有史以来对乐山市波及范围最广、人员伤亡最多、经济损失最大、社会影响最强烈的地震。本文回顾了近几年乐山市在地震应急准备方面所做的工作和汶川特大地震波及乐山后的应急工作,认为坚持不懈地抓好地震应急准备是做好大地震之后应急工作的重要前提,及时有效地开展应急工作是防震减灾部门的重要职责,震后恢复重建中防震减灾部门可以发挥重要作用。     

丹江口库区本底地震与水库地震趋势分析

从丹江口库区地震地质构造着手,总结公元前143年至公元2008年本底地震活动情况,分析在初期蓄水阶段水库诱发地震活动情况、强度及成因。讨论丹江口水库增容后,新增库水对库区的应力状态影响,探讨库区及周缘地区可能诱发水库地震的区域及强度。结果发现,丹江口库区中的汉库诱发地震可能性不大。而丹库可能诱发地震,其强度应在M≤5.0。主要诱发地震危险区仍在丹库宋湾—关防滩峡谷地形库段和林茂山—凉水河地区。     

应用灰色聚类法预测小浪底水库诱发地震最大震级

根据野外考察并结合前人研究成果,对黄河小浪底水库及其邻区地震地质背景进行了分析,对其区域应力状态、断层活动性、地层岩性和地震活动背景等水库诱发地震因素进行了研究。简要地介绍了灰色聚类法,并应用该方法对小浪底水库发生水库诱发地震的可能性及诱发地震震级进行了预测。结果表明,该水库存在水库诱发地震的可能性,其最可能诱发地震的地段及库区中段,水库诱发地震最大震级预测为５级。     

水口水库地震对南平地区的影响

水口水库建成蓄水后诱发了频繁的地震活动，延续时间已达8年之久，,学在继续活动。近年来，南平地区的邵武，政和等地也相继有中小地震活动，为了摸清南平地区地震活动与水口水库诱发地震是否关联，本文对该地区及水口水库诱发地震前后的地震活动性及时空特征，区域构造背景及水库诱发地震的活动趋势进行综合分析研究。     

从九江-瑞昌5.7级地震与人员伤亡所想到的

简要介绍了九江—瑞昌地震的基本情况与特点。针对此次地震波及范围广、社会影响大与人员伤亡重的现象,与日本的抗震减灾对策及新疆近年几次中强地震的快速应急反应进行比较分析。初步探讨了几种灾害类型与地震灾害的预防。最后给出几点结论。     

Stone columns as liquefaction countermeasure in non-plastic silty soils

In many cases densification with vibro-stone columns cannot be obtained in non-plastic silty soils. Shear stress re-distribution concepts [1] have been previously proposed as means to assess stone columns as a liquefaction countermeasure in such non-plastic silty soils. In this study, centrifuge testing is conducted to assess the performance of this liquefaction countermeasure. Attention is focused on exploring the overall site stiffening effects due to the stone column placement rather than the drainage effects. The response of a saturated silt stratum is analyzed under base dynamic excitation conditions. In a series of four separate model tests, this stratum is studied first without, then with stone columns, as a free-field situation, and with a surface foundation surcharge. The underlying mechanism and effectiveness of the stone columns are discussed based on the recorded dynamic responses. Effect of the installed columns on excess pore pressures and deformations is analyzed and compared. The test results demonstrate that stone columns can be an effective technique in the remediation of liquefaction induced settlement of non-plastic silty deposits particularly under shallow foundations, or vertical effective stresses larger than about 45 kPa (1000 psf) in free field conditions.     

中国海域及其相邻海域地震烈度区划图及简要说明

我国具有辽阔的海域,随着国民经济的发展,我国海域资源的开发和利用将日趋重要,海上活动愈来愈频繁。因此编制中国海域及其相邻海域地震烈度区划图(它是海域地震对策的组成部份)就成为十分必要的了。由于我国海域地震资料和地质构造资料较少,精度较差,故已往未进行过海域地震烈度区划。本文综合研究了海域地震资料、地质资料、地形资     

Effect of soil stabilization on audible band railway ground vibration

Although railway-generated ground vibrations usually have greater energy levels at lower frequencies, vibrations in the audible range above 20 Hz can nevertheless be relevant for secondary noise problems in buildings. One countermeasure is soil stabilization under the track embankment. While effective at low frequencies, a potential side effect is amplification in some audible bands. Presented here are both experimental and theoretical assessments of the countermeasure in the audible bands. The main innovation is the treatment of an infinite periodic track–ground system, using a transfer matrix approach with a repeating element including the rail, pad, sleeper, and an underlying half-space (ballast and soil). Excitation in this band is attributed to rail and wheel roughness. The model makes successful predictions when the half-space properties are allowed to be frequency-dependent such that the dispersion of the surface wave matches that in the actual layered earth (including ballast and underlying soil layers). The field measurements are also unique in that both before and after evaluation of the countermeasure was possible.     

Protection of bridge piers against scouring with tetrahedral frames

Armoring countermeasures, such as riprap stones, are the primary method used to protect bridge piers against scouring; however, these methods have not had definitive success. Recently, flow-altering countermeasures, such as sacrificial piles, have been tested as an alternative to armoring countermeasures. This study investigated the mechanics of an innovative flow-altering countermeasure device, frames in the shape of tetrahedrons that act as a pier-scour countermeasure. Results of measured characteristics for turbulence flow showed that the flow around the tetrahedral frames can be divided into three regions： （1） a deceleration region near the sediment bed; （2） an acceleration region in the middle of water depth region; and （3） a restoration region near the water surface. The velocity magnitudes, turbulent intensities and vorticities decreased in the deceleration region, increased in the acceleration region and reverted to that of the unprotected condition in the restoration region. This pier-scour countermeasure is innovative because of its ability to dissipate energy associated with the downflow and the horseshoes vortex generated around the bridge pier. The scour tests revealed that the frames protected the foundation of bridge piers against scour. The experimental results showed that the percentage reduction of scour depth decreased as the velocity ratio, U/U c , decreased, reaching a value of 50% for the range of parameters tested in this study. Moreover, its efficiency was dependent on the placement density of the frames. The data showed that the frames were more effective when η was larger. However, their influence becomes less significant when η≥ 0.16.     

浅谈加强广东防震抗灾问题

本文从加强广东防震抗灾工作的意义和对策二部分进行分析,指出在致力发展经济的同时,更应重视防震减灾工作,使防震减灾工作同经济建设和社会发展相适应。并从增强意识、以防为主、综合防御、落实措施这4方面详述加强广东防震抗灾工作所采取的对策。     

Bridge pier scour mitigation under steady and unsteady flow conditions

Watercourse morphology is affected by local scouring when the flow interferes with anthropic structures. Controlling the scour hole size is of predominant importance to guarantee bridge safety as well as to limit the variations of river morphology. A combined countermeasure against bridge pier scour is proposed and tested in order to reduce the maximum scour depth and deviate it away from the bridge foundation. In the first part of the laboratory campaign, combination of two countermeasures (bed-sill and collar) was evaluated for a circular pier under clear-water and live-bed steady flow conditions. The proposed combined countermeasure exhibited an efficiency of about 64% in terms of scour depth reduction. Afterwards, it was tested in unsteady flow conditions, first for a circular pier, then in the case of a rectangular pier with round nose and tail, two circular in-line piers and two rectangular in-line piers, under a hydrograph with a peak flow velocity slightly above the threshold condition of sediment motion. Results showed that the combined countermeasure had an efficiency of about 63% for a single circular pier; however, higher efficiency (about 75%) was obtained in applications to rectangular pier and two in-line circular or rectangular piers.     

长白山天池火山减灾对策初探

国内外专家学者认为，长白山天池火山是一座具潜在灾害性喷发危险的活火山，因此制定火山减灾对策理应提到议事日程。针对天池火山研究现状和火山灾害特点，制定了火山活动各阶段的减灾对策。中长期阶段应加强火山监测与研究和火山知识宣传工作，采取必要的工程防护措施，重大工程进行火山安全性评价，制定火山喷发应急预案；短期阶段请求国际火山流动监测台网给予支援；临近喷发阶段重点是有组织的撤离；喷发及其后阶段应及时救灾抢险，对火山喷发趋势进行科学判定，合理地重建家园。     

地震预报和地震对策模型体系

设计了一种用于地震预报和地震对策的模型体系。本文简述了建立这一模型体系的必要性,给出了模型体系的设计思想,讨论了模型体系的結构、功能和组成以及建立模型体系的数学方法。     

包头6．4级地震灾害特点及城市地震对策

分析总结了1996年包头6.4级地震的地震地质背景、工程场地条件及地震灾害特点,介绍了包头市的城市地震防御措施和应急对策,提出城市地震应急对策的主要问题。