Geotechnical Aspects of the January 13, 2001 El Salvador Earthquake

An earthquake of magnitude 7.6 occurred in the south-east coast of El Salvador on January 13, 2001, causing widespread damage to buildings and several kinds of civil engineering structures due to ground shaking and earthquake-induced ground failures, including several large-scale landslides. This paper discusses the results of the damage investigation conducted in the area after the earthquake, with emphasis on the general features of the earthquake and its effects on the ground damage, specifically the landsliding which occurred in natural slopes and the liquefaction of soil deposits. The occurrence of liquefaction in the alluvial plain exhibited several characteristics in common with those observed in other areas of similar condition. On the other hand, the main cause of slope failures in volcanic deposits was not clearly identified, and several possible sources of slope instability were pointed out.     

Urbanization and land-use planning in Adapazari (Turkey) reconsidered after the 1999 earthquake

On 17 August 1999, an earthquake with a magnitude of 7.4 struck the Eastern Marmara Region of Turkey, destroying hundreds of buildings and killing thousands of people. It is not enough to analyze the damage inflicted by the earthquake solely in terms of its physical features (magnitude, epicenter or depth). Regional policies (particularly industrialization and urbanization) and unsuitable land-use planning/engineering processes also played a role. This paper presents a critical evaluation of these factors with reference to Adapazar, one of the cities that suffered heavily from these non-natural processes.     

Microzonation for Seismic Geotechnical Hazards and Actual Damage During the 2005 Fukuoka-Ken Seiho-Oki Earthquake

The 2005 Fukuoka-ken Seiho-oki earthquake caused damage to structures due to liquefaction, slope failure and strong shaking in Fukuoka City. One of the authors had conducted microzonation for liquefaction, slope failure and strong shaking about 17 years before the earthquake. After the earthquake, the authors compared the zoning map with the actual damage. The results showed that liquefied sites coincided fairly well with predicted zones in the reclaimed lands. However, they were slightly different in a big sand spit named Uminonakamichi. Failure occurred at several slopes inside the predicted areas, while damage to buildings occurred due to strong shaking along the Kego Fault. The damaged area was slightly different from the predicted area. Furthermore, a liquefaction analysis was conducted and the results of this analysis were compared with the results of microzonation in 1988. In this paper, the authors discuss the validity of microzonation based on this comparison.     

Geotechnical Aspects of the Sumatra Earthquake of September 30, 2009, Indonesia

This paper reports and discusses the results of a field survey conducted by a joint scientific group from Japan and Indonesia to assess the geotechnical aspects of the Sumatra earthquake (M_w=7.6) of September 30, 2009. The studied area included the Padang and Pariaman cities, where a number of buildings collapsed as a result of strong shaking, and a mountainous part of the Pariaman district, a place where massive landslides buried several villages, claiming more than 400 human lives. The main objective of the survey was to investigate the causes and mechanisms of catastrophic landslides; however, other geotechnical problems such as lateral spread and liquefaction were also addressed. Field observations indicated that the catastrophic landslides occurred on relatively gentle slopes, then mobilized into debris flows, and traveled several hundred meters from their points of origin. The failure surfaces developed along the boundary of highly weathered pumice tuff with more intact and less weathered bedrock. Data from a portable cone penetration test showed that the sliding material was rather weak, having SPT N-values in the range of 5-10. The results of the field survey suggested that the main cause of slope instability was high pore-water pressures that generated in the soil mass during the earthquake.     

Investigation of Lake Sapanca water pollution,Adapazari, Turkey

Lake Sapanca has been the only source of drinking and recreational water for the city of Adapazari, Turkey. This paper reports a study of the variation of nutrient loading and trophic state of the lake, and also water quality parameters of Lake Sapanca compared to those of the neighbouring Lake Iznik. Through one year, samples were taken every three months from 15 different points on the streams feeding and draining off the lake. Nitrate, NO₂‐N, NH₃‐N, TKN, PO₄‐P concentrations on the 12 streams fe and three draining off points were determined. Then, loading, discharge, and accumulation amounts of nitrogen and phosphorus causing eutrophication were calculated and the trophic state of the lake was determined. A simple model was used to analyse the response of Lake Sapanca when the phosphorus loading rate was changed. Through this model, the variation of different parameters (t, M, K, Q, V and A) with respect to phosphorus concentration (C) was studied to identify effects and results. The consequences of an eutrophic state and measures to protect the lake are also discussed.     

Geotechnical Reconnaissance Study on Damage Caused by 2001 Gujarat Earthquake,India

The Gujarat earthquake in India occurred in January, 2001, and caused significant damage in the province of Gujarat. The Japanese Geotechnical Society sent a small reconnaissance team to the damaged region after the quake. The present text presents the report from this activity. The major attention of the team was focused on geotechnical aspects of the damage which were related to earthfill dams and harbor land fills. It was found that a significant portion of damage was concentrated in fills resting on soft natural soils. Swedish weight soundings which were conducted at two places demonstrated the existence of such a soft subsoil. From this, it was concluded that amplification of earthquake shaking as well as the permanent deformation in the soft foundation soil induced such kinds of damage as subsidence, cracking, and lateral spreading in overlying artificial fills. For the better seismic resistance of those affected fills during future earthquakes, the improvement of soft subsoil seems essential.     

Geotechnical Aspects of Groundwater Control

Due to the increasing world population growth and competition for space, especially in bigger cities, the construction of subsurface civil engineering structures has become unavoidable. Safety, both during and after the construction of such structures, is of paramount importance to civil engineers. One of the main challenges in securing this safety is presented in the form of groundwater flow and its control. In this paper, the state of the art techniques for controlling groundwater flow during underground excavation are outlined with case studies from some construction sites in Japan. It needs to be pointed out that no single technique is adequate for controlling groundwater flow at an excavation site. Also, not so much attention has been paid to the designed groundwater level, which plays a major role in the stability of the structure after construction. In addition, groundwater conservation has yet to be considered in the designs of such structures. It is necessary for by-passes for groundwater flow to be constructed and monitored over the long term to assess their performances.     

台湾921地震中钢筋混凝土结构震害特征

本文介绍在 1999年 9月 2 1日台湾集集大地震中钢筋混凝土建筑结构的各种典型破坏特征 ,包括短柱破坏效应、剪切效应、剪压破坏、压屈破坏、弯剪破坏、梁柱塑性铰、钢筋锚固不足破坏、混凝土酥碎破坏等。文中分析探讨了震害的原因及吸取的教训     

南京地铁工程岩土勘察的若干问题探讨

近年来,随着我国城市化进程的不断加快,城市人口呈现大规模增长趋势,由此带来的城市交通压力不容小觑。为了缓解这种压力,以地铁为代表的城市轨道交通工程逐渐兴起,而由于地铁设计要求的特殊性和地铁建设场地地质条件的多样性使得地铁工程岩土勘察具有较为鲜明的"个性"。现结合宁天城际轨道交通一期工程雄州站~凤凰山公园站地铁隧道区间的特定地质条件,从场地的稳定性及工程的适宜性、岩土层工程地质评价、地基均匀性评价、特殊岩土以及不良地质等方面出发对南京地铁工程勘察研究的主要内容进行了介绍,并提出了地铁工程勘察中需要注意的问题。     

岩土工程勘察质量控制要点

规范岩土工程勘察质量管理行为是确保岩土工程勘察质量的关键所在。探讨了岩土工程勘察过程中质量控制的几个主要方面,分别就施工前、施工阶段及后续阶段的勘察质量控制作了分析。     

土耳其伊兹米特地震震害考察

文章介绍了 1999年土耳其伊兹米特地震和震害概况 ,并结合现场考察对建 (构 )筑物和生命线工程的震害特点和破坏原因做了讨论和分析。     

汶川地震中绵竹公共建筑的震害调查与分析

四川汶川8.0级特大地震造成了绵竹市大量学校、医院和宾馆等公共建筑的倒塌和严重损坏,造成了巨大的人员伤亡和经济损失。本文介绍了绵竹市学校、医院、宾馆等公共建筑比较有代表性的震害调查结果,分析了此次地震中砌体、框架、砌体-钢筋混凝土混合结构的震害特点和震害原因;在此基础上,总结了一些经验和教训,提出了几点抗震设计建议,供实际工程应用和修编相应规范参考。     

Geotechnical Aspects of Current Underground Construction in Japan

The Japanese National Committee for TC28 has produced a committee report on current underground construction activities in Japan, including the technologies of braced excavation and tunneling.This report is based on technical papers and available construction records from the past decade. In the field of braced excavation, the topics of proximity construction, excavation machines for braced walls, deep shaft excavation, and groundwater flow preservation measures have been selected and introduced, along with some case records. In the field of tunneling, statistical data on tunneling in Japan has been assembled from published data and questionnaires. Several case records using current shield tunneling and urban NATM methods are described. Finally, damages to underground structures due to the 1995 Hyogoken-Nanbu (Kobe) Earthquake are summarized, and new earthquake­ resistant designs for shield tunneling and other technologies are introduced.     

结构在地震动时延性和累积塑性耗能的双重破坏准则

本文运用经改进后可以计算结构弹塑性能量时程反应的数值积分法计算程序,分別把实际地震记录和人工地震波输入到八座在唐山地震中遭受不同程度破坏的实际结构计算模型中,进行结构弹塑性变形和能量反应的计算。将计算结果和实际震害情况相比较,从中探讨并得到同时考虑结构的变形能力和累积塑性耗能、较便于实际应用的双重破坏控制指标。     

NJUT在岩土地震工程领域的研究进展

本文回顾了南京工业大学(Nanjing Unversity of Technology,NJUT)在岩土地震工程领域开展的理论和试验研究工作,主要内容包括:地基土液化、土动力特性、场地地震效应、土与结构动力相互作用以及重大工程结构(桥隧、地铁车站、土石坝、高层建筑)地震反应特性等。文中简要介绍了以上工作所取得的主要创新性成果以及工程应用情况,并对今后研究方向进行了展望。     

桥梁震害与抗震设计

对桥梁震害进行分类,论述减隔震技术的原理及适用条件,从基础、桥台、支座、型钢等角度论述抗震设计方法.     

岩土工程学报1999年的两种影响因子

1　引　　言 学术质量是科技期刊赖以生存和发展的关键 ,而评价科技期刊学术质量的指标更为广大科技工作者特别是期刊编辑部门和管理部门所关注。期刊每年的影响因子、总被引频次和即年指标等从一个侧面反映了期刊论文的学术水平 ,因而对科技期刊的质量评价具有特别重要的意义 ,已成为评价科技期刊质量的几项重要指标。但影响这些指标值的因素很多 ,其中尤以确定它们的大小时所采用的统计用期刊 (以下简称来源期刊 )的数量有关。本文就 1999年由两种数量不同的来源期刊所统计出的《岩土工程学报》在当年的两种影响因子值[1,2 ] 进行分析和探讨。2　影响因子的含义和确定方法影响因子又称期刊论文的平均被引率 ,是指期     

绵阳市房屋震害分析及震后加固方法研究

汶川地震中,绵阳市大部分房屋均有不同程度破坏.本文对绵阳市砖混结构、框架结构房屋所受震害、加固方案进行分析,对施工过程进行了跟踪调研.经过几次明显震感的余震后,经检测,加固过的房屋未出现任何破坏,表明:(1)依据现行相关规范要求进行加固的房屋,抗震能力明显增强.(2)依据墙体破坏程度和墙体承重与否,对墙体采用不同的加固...