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1.
武汉市城市建设和发展中的若干环境地质问题 总被引：1，自引：0，他引：1
环境地质问题的解决关系到城市可持续发展的实现，本文对武汉市城市地质环境及场区地震、环境地质因素、江、湖水质、洪泛及地面渍害、三峡工程及影响等进行了论述。从而认为应把研究和防治武汉城市环境地质灾害及环境恶化作为一项重要的、长期的工作来开展，并纳入城市总体规划和管理的大系统之中。 相似文献
2.
在区域稳定性评价中,其主要内容之一就是地震稳定性评价。近年来,国内外多采用地震危险性分析的概率方法作为区域地震稳定性评价的主要方法。 在地震危险性分析中,首要问题是确定区域潜在震源,但至今尚缺乏完整、科学的理论和实践。作者认为有必要从地震地质角度进行一次深刻的地质反思。 本文从构造变形的动力源、区域及局部应力场、地震断裂活动带的地震重复周期,地震断裂的活动特征及区域地震强度衰减规律等几个方面提出了若干看法,作为地震危险性分析的基础地震地质工作加以考虑。至于常见的非发震断裂在区域地震稳定性评为中所起的作用,则需对这些断裂的地质特征与周围地质体的介质特征进行具体的对比分析,才能判定其对地震波传播的影响,不能一概而论。 相似文献
3.
城市地质灾害危险性评价浅析 总被引：5，自引：0，他引：5
由于人口高度集中、建筑密集,加之人类工程活动对地质环境的改造强烈,城市地质灾害发生的强度和频度也相应较高.地质灾害危险性评价是城市规划的依据,对城市发展至关重要.城市的自然条件、地质环境和城市功能不同,其存在的地质灾害类型和灾害严重程度也不同,大体可分为平原城市、山区城市、沿海城市、矿业城市四种基本类型分别进行灾害危险性评价.危险性评价的主要步骤为初步确定可能发生的灾害类型;分别对各单一灾种进行危险性评价;将单一灾种评价的结果叠加,得出城市地质灾害危险性综合评价成果,即地质灾害危险性区划(一般划分为4个等级).在危险性评价的基础之上,建立灾害预测预报和监测系统,进而应逐步建立和完善城市地质灾害防御系统. 相似文献
4.
赵忠海 《中国地质灾害与防治学报》2011,22(3):106-112
近年来,人类工程活动引发的地质环境问题日益严重,因此在城市建设规划阶段,进行地质环境适宜性的分析与评价十分必要。本文在门头沟规划新城前期区域工程地质勘查工作基础上,通过对区域工程地质条件、水文地质条件、地质灾害危险性、工程建设场地适宜性以及规划建设对地质环境的影响程度等主要因素进行综合分析与研究,对门头沟新城规划分区的地质环境适宜性进行了评价与探讨。认为该新城规划分区的地质环境总体来说是适宜或基本适宜的,但个别功能分区的地质环境不适宜。对于基本适宜及不适宜的功能分区,指出了其存在的主要地质环境问题,并提出了有针对性的建议。 相似文献
5.
武汉市是我国大城市之一,是华中经济、交通中心,又是经济体制改革试点城市。但长期以来武汉地区没有大比例尺的区域地质、区域矿产和区域环境地质图件,城市发展的区域地质背景不很清楚,影响城市的规划和建设。为此,湖北地矿局根据地矿部关于加强城市地质工作的指示精神,于1985年快速编制了一套武汉市1:5万地质图系。1986年4月1日至3日,地质图系经武汉市经委、科委、规划局、勘测院、省测绘局、地矿局等单位评审。认为该图系基本反映了武汉地区最新地质研究成果,是武汉市进行规划、建设的一份较好的基础地质资料,同意验收,尽快出版提供省、市各单位使用。 相似文献
6.
在某工程的区域稳定性研究和水库区工程地质调查的基础上,综合分析了水库的区域地震地质条件。依据实际存在的诱发地震条件组合,对该水库诱发地震的环境进行了分区评价。重点研究了水库区地质背景、水库诱发地震的关键因素及水库诱发地震的潜在危险性预测等方面。研究表明水库在运行过程中有发生裂隙断块岩体型或裂隙喀斯特岩体型诱发地震的可能性,但诱发地震强度仅为微震或弱震,其基本烈度不会超过历史构造地震对区内的影响。 相似文献
7.
水库诱发地震评价研究 总被引：1，自引：0，他引：1
夏其发 《中国地质灾害与防治学报》2000,11(3):32-35
本文是在总结了水库地震的基本情况和主要特征后,以工程地质学理论为基础,并结合地震地质学,对水库地震进行了评价.其目的是为了确保大坝施工期与建成后的安全运行,并根据库坝区的诱震地质条件,正确评价诱发地震的可能性及其可能造成的危害,为工程建设采取合理的对策提供依据.其步骤分为3步:水库地震可能性评价、水库地震危险性评价与水库地震监测和预测研究.其内容为区域工程地质、构造地质、水文地质、地震与水库地震监测,并依据世界水库地震资料的对比分析,总结出:构造断裂型、地表卸荷型与岩溶塌陷型3种主要水库地震类型的判据.其评价方法,主要是对水库地震综合性分区评价及水库地震强度的评价方法进行了详细的论述,具有较高的实用价值. 相似文献
8.
水库诱发地震评价研究 总被引：4，自引：0，他引：4
夏其发 《中国地质灾害与防治学报》2000,11(2):39-45
本文是在总结了水库地震的基本情况和主要特征后,以工程地质学理论为基础,并结合地震地质学,对水库地震进行了评价。其目的是为了确保大坝施工期与建成后的安全运行,并根据库坝区的诱震地质条件,正确评价诱发地震的可能性及其可能造成的危害,为工程建设采取合理的对策提供依据。其步骤分为三步：水库地震可能性评价、水库地震危险性评价与水库地震监测和预测研究。其内容为区域工程地质、构造地质、水文地质、地震与水库地震监测,并依据世界水库地震资料的对比分析,总结出：构造断裂型、地表卸荷型与岩溶塌陷型3种主要水库地震类型的判据。其评价方法,主要是对水库地震综合性分区评价及水库地震强度的评价方法进行了详细的论述,具有较高的实用价值。 相似文献
9.
《西北地质》2016,(2)
基于构造地质、地层岩性、地震、水文地质、岩土工程地质条件分析,以及庞庄煤矿老采区煤层开采资料分析,应用残余变形概率积分法,预测计算了庞庄煤矿工业广场的地表残余变形,评价了其场地稳定性,并分析了庞庄煤矿开采对环境地质的影响。庞庄煤矿开采对地质环境的影响特别重大,其影响主要表现为包括原始地形地貌、地表水、工程地质和水文地质条件的破坏。庞庄煤矿工业广场的最大残余变形量拐点连线(计算边界)处最大残余倾斜值i_m=3.02~3.28mm/m3.0mm/m,残余倾斜(i_m)可能对拟建工程局部构成危害。笔者将拟建工程区的地质灾害危险性划分为3个区。Ⅰ区和Ⅱ区分别为危险性小区和危险性中等区,为适宜和基本适宜场地;Ⅲ区危险性大,场地适宜性差,需地基工程治理。评价工作为徐矿集团华美2×300MW(CFB)机组工程机组建设工程提供了场地安全保证,同时,为合理利用宝贵的庞庄煤矿工业广场土地资源,提高土地综合利用率,提供了坚实依据。 相似文献
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11.
India is prone to earthquake hazard; almost 65 % area falls in high to very high seismic zones, as per the seismic zoning map of the country. The Himalaya and the Indo-Gangetic plains are particularly vulnerable to high seismic hazard. Any major earthquake in Himalaya can cause severe destruction and multiple fatalities in urban centers located in the vicinity. Seismically induced ground motion amplification and soil liquefaction are the two main factors responsible for severe damage to the structures, especially, built on soft sedimentary environment. These are essentially governed by the size of earthquake, epicentral distance and geology of the area. Besides, lithology of the strata, i.e., sediment type, grain size and their distribution, thickness, lateral discontinuity and ground water depth, play an important role in determining the nature and degree of destruction. There has been significant advancement in our understanding and assessment of these two phenomena. However, data from past earthquakes provide valuable information which help in better estimation of ground motion amplification and soil liquefaction for evaluation of seismic risk in future and planning the mitigation strategies. In this paper, we present the case studies of past three large Indian earthquakes, i.e., 1803 Uttaranchal earthquake (Mw 7.5); 1934 Bihar–Nepal earthquake (Mw 8.1) and 2001 Bhuj earthquake (Mw 7.7) and discuss the role of soft sediments particularly, alluvial deposits in relation to the damage pattern due to amplified ground motions and soil liquefaction induced by the events. The results presented in the paper are mainly focused around the sites located on the river banks and experienced major destruction during these events. It is observed that the soft sedimentary sites located even far from earthquake epicenter, with low water saturation, experienced high ground motion amplification; while the sites with high saturation level have undergone soil liquefaction. We also discuss the need of intensifying studies related to ground motion amplification and soil liquefaction in India as these are the important inputs for detailed seismic hazard estimation. 相似文献
12.
In this paper, seismic risk scenarios for Bucharest, the capital city of Romania, are proposed and assessed. Bucharest has one of the highest seismic risk levels in Europe, and this is due to a combination of relatively high seismic hazard and a building stock built mainly before the devastating Vrancea 1977 earthquake. In this study, the seismic risk of Bucharest is assessed using the most recent information regarding the characteristics of the residential building stock. The ground motion amplitudes are evaluated starting from random fields obtained by coupling a ground motion model derived for the Vrancea intermediate-depth seismic source with a spatial correlation model. The seismic risk evaluation method applied in this study is based on the well-known macroseismic method. For several structural typologies, the vulnerability parameters are evaluated based on a damage survey performed on 18,000 buildings in Bucharest after the March 1977 earthquake. Subsequently, the risk metrics are compared with those from other studies in the literature that apply a different risk assessment methodology in order to gain a better view of the uncertainties associated with a seismic risk study at city level. Finally, the impact of several Vrancea intermediate-depth earthquake scenarios is evaluated and the results show that the earthquake which has the closest epicenter to Bucharest appears to be the most damaging.
相似文献13.
In this paper, seismic risk scenarios for Bucharest, the capital city of Romania, are proposed and assessed. Bucharest has one of the highest seismic risk levels in Europe, and this is due to a combination of relatively high seismic hazard and a building stock built mainly before the devastating Vrancea 1977 earthquake. In this study, the seismic risk of Bucharest is assessed using the most recent information regarding the characteristics of the residential building stock. The ground motion amplitudes are evaluated starting from random fields obtained by coupling a ground motion model derived for the Vrancea intermediate-depth seismic source with a spatial correlation model. The seismic risk evaluation method applied in this study is based on the well-known macroseismic method. For several structural typologies, the vulnerability parameters are evaluated based on a damage survey performed on 18,000 buildings in Bucharest after the March 1977 earthquake. Subsequently, the risk metrics are compared with those from other studies in the literature that apply a different risk assessment methodology in order to gain a better view of the uncertainties associated with a seismic risk study at city level. Finally, the impact of several Vrancea intermediate-depth earthquake scenarios is evaluated and the results show that the earthquake which has the closest epicenter to Bucharest appears to be the most damaging. 相似文献
14.
L. Thoithoi C. S. Dubey P. S. Ningthoujam D. P. Shukla R. P. Singh S. S. Naorem 《Journal of the Geological Society of India》2016,88(2):147-150
The study area Delhi is second most populous city and third largest urban area in the world. Though the area lies in seismic high damage risk zone, number of high rise building and construction of mega structure at several sites of the city increase rapidly. In this study field Standard Penetration Test (SPT) values of soil collected from 750 boreholes data were analyzed to identify liquefiable sub-surface soil layers. Finally, liquefaction susceptible sub-surface maps of the region at various depth (20 m, 15 m, 12 m, 9 m, 6 m and 3 m) from ground level is prepared. The outcome of this study will be useful input for preliminary foundation and designing of earthquake resistant high rise building and seismic microzonation studies of Delhi. 相似文献
15.
场地土对基岩峰值加速度放大效应分析 总被引：1，自引：2，他引：1
通过实际土层地震反应结果的统计分析和强震加速度观测结果的对比, 讨论了不同场地条件对基岩峰值加速度的放大效应及其特点。该分析可为地震动参数区划图编制和地震安全性评价中场地效应的估计、由基岩地震动估算场地地面地震动提供参考。 相似文献
16.
A methodology to model seismic microzonation maps is required in the hazard mitigation decision plans of the earthquake prone areas. The stage of disaster preparedness for new residential places is of great importance for detailed seismic microzonation models. The effects of local geological and geotechnical site conditions were considered in order to establish site characterization as the initial stage of the models in this study. Dynamic soil properties based on the empirical correlations between shear wave velocity (V s) and standard penetration test blow counts were taken into account in order to define representative soil profiles extending down to the engineering bedrock. One-dimensional site response analyses were performed to analyze earthquake characteristics on the ground surface. The layers for soil classification, geology, depth to groundwater level, amplification, distance to fault, slope and aspect, and liquefaction-induced ground deformation potential of the study area were prepared in seismic microzonation models. The study area, Erbaa, is placed along the seismically active North Anatolian Fault Zone. Final seismic microzonation map of the study area was evaluated applying different GIS-based Multi-Criteria Decision Analysis (MCDA) techniques. Two of the MCDA techniques, simple additive weighting and analytical hierarchical process (AHP), are considered during the evaluation step of the final seismic microzonation map. The comparison is made in order to distinguish two different maps based on these MCDA techniques. Eventually, AHP-based seismic microzonation map is more preferable for the seismic design purposes in this study. 相似文献
17.
极震区岩体地震动力破坏若干问题探讨 总被引：2，自引：0，他引：2
汶川地震时极震区产生了严重的地震地质灾害,其中强烈地震动造成的岩体动力破坏是造成灾害的根本原因。从极震区含义、地震动特征、岩体地震动力破坏概念、地震松动岩体和方法论等方面初步探讨了极震区岩体地震动力破坏问题。极震区是未来地震的潜在震源区,区内的地震属于直下型。极震区地震动具有不同于非极震区的地震动特征,岩体地震动力破坏的复合性特点就是地震动的不确定性造成的。对极震区岩体动力破坏概念的理解应考虑地震动的特点。地震松动岩体是极震区地震动造成的一种特殊破坏类型,是形成震害次生灾害的重要原因。岩体工程地质力学等学科的思想方法和技术手段为研究极震区岩体地震动力破坏这一命题提供了良好的基础,预测和评价极震区因岩体动力破坏造成的工程震害和地质灾害,减轻和预防未来地震时的灾害损失,是极震区岩体地震动力破坏研究的目标和方向。 相似文献
18.
简要地总结了当前地震小区划工作中有关砂土液化的判别、地基土震陷、土坡稳定性、土动力参数测定及土层地震反应分析等方面的土动力学问题。评述了地震小区划工作中涉及的上述土动力学问题的研究方法和工程应用情况。讨论了在这一研究领域内存在的科学问题和今后的研究方向。 相似文献
19.
远场大地震作用下大尺度深软场地的非线性地震效应分析 总被引：1，自引：0，他引：1
基于ABAQUS软件自行研制的并行计算显式算法集群平台,针对苏州城区典型地层剖面,建立了大尺度深软场地的二维精细化非线性有限元分析模型,对人工地震波和大地震远场地震动作用下深软场地的非线性地震效应进行了比较研究。研究结果表明：（1）与人工地震波作用时深软场地的地表峰值加速度放大效应相比,大地震远场地震波作用时的放大效应尤为显著,由于土介质的横向不均匀性及其非线性,使不同地表的峰值加速度放大效应存在明显的变异性。（2）深软场地对周期小于0.3 s的高频地震波均具有显著的滤波效应;大地震远场地震波作用时,深软场地对周期0.85～1.65 s的长周期地震波的放大效应非常显著,但对2.5～7.0 s的长周期地震波呈现出明显的滤波效应。（3）地震动峰值加速度PGA值沿土层深度和横向的分布形态呈现出明显的高低起伏现象,在不同成因的土层更迭面附近及土介质横向不均匀性显著的区域,地震波的局部聚焦放大和过滤减小现象尤为明显,且大地震远场地震动作用时,20 m以浅土层的PGA值呈现出非常显著的放大效应。（4）地震波的频谱特性、土层的横向不均匀性对深软场地地表加速度反应谱? 谱的谱形有显著影响;给出了描述加速度反应谱沿土层深度变化特征的三维谱形曲线,可以直观地展示出深软场地中细长地下结构地震反应可能存在类共振现象的土层深度。 相似文献
20.
This paper highlights the seismic microzonation carried out for a nuclear power plant site. Nuclear power plants are considered to be one of the most important and critical structures designed to withstand all natural disasters. Seismic microzonation is a process of demarcating a region into individual areas having different levels of various seismic hazards. This will help in identifying regions having high seismic hazard which is vital for engineering design and land-use planning. The main objective of this paper is to carry out the seismic microzonation of a nuclear power plant site situated in the east coast of South India, based on the spatial distribution of the hazard index value. The hazard index represents the consolidated effect of all major earthquake hazards and hazard influencing parameters. The present work will provide new directions for assessing the seismic hazards of new power plant sites in the country. Major seismic hazards considered for the evaluation of the hazard index are (1) intensity of ground shaking at bedrock, (2) site amplification, (3) liquefaction potential and (4) the predominant frequency of the earthquake motion at the surface. The intensity of ground shaking in terms of peak horizontal acceleration (PHA) was estimated for the study area using both deterministic and probabilistic approaches with logic tree methodology. The site characterization of the study area has been carried out using the multichannel analysis of surface waves test and available borehole data. One-dimensional ground response analysis was carried out at major locations within the study area for evaluating PHA and spectral accelerations at the ground surface. Based on the standard penetration test data, deterministic as well as probabilistic liquefaction hazard analysis has been carried out for the entire study area. Finally, all the major earthquake hazards estimated above, and other significant parameters representing local geology were integrated using the analytic hierarchy process and hazard index map for the study area was prepared. Maps showing the spatial variation of seismic hazards (intensity of ground shaking, liquefaction potential and predominant frequency) and hazard index are presented in this work. 相似文献