汶川8.0级地震北川县城区灾害调查与分析

2008年5月12日发生了汶川8．0级特大地震,震后作者深入地震重灾区开展了震害现场调查工作。利用现场调查得到的第一手资料,分析了极震区北川县城区的震害现象,发现山坡和河岸滑坡、断层地表破裂以及柔底层结构底层破坏所导致的结构严重破坏和倒塌是城区的主要震害现象,同时看到仍然有一些砌体结构建筑震害较轻,处于轻微或中等破坏,甚至基本完好状态。这些震害现象展示了山区地震灾害的基本特征和复杂性。     

对1976年河北唐山MS7.8地震地表破裂带展布及位移特征的新认识

1976年河北唐山MS7.8地震发生之后,诸多资料报道了唐山市南侧展布的长8～11km的地震地表破裂带.该地表破裂带由10余条NE方向、具右旋走滑特征的地表破裂呈左阶形式组成,总体走向N30°E,最大右旋位移2.3m,多数地段的垂直位移为0.5 ～0.7m.近年有学者提出,在更大范围内出现的地表破坏现象.分辨这些地表破...     

汶川8.0级地震地表变形局部化样式与建筑物破坏特征关系初步研究

以汶川地震地表形变带的实地测量数据为基础,结合沿实测地震地表变形剖面建筑物破坏情况的调查与测量,分析了不同地震地表变形类型及其建筑物破坏特征,定量化地讨论了地表变形梯度与建筑物破坏程度间的关系.提出无论地震地表变形表现为何种类型的断层陡坎,强变形均局部化在宽10~30 m的地表破裂带内;建筑物受损情况最直接的影响是建筑物所处地点的地表变形梯度,地表变形梯度大于0.1的地段,建筑物均完全被摧毁;地表变形梯度在0.07~0.1间的地段,建筑物遭受严重损坏,产生倾斜及强烈变形等;地表变形梯度在0.03~0.07间的地段,建筑物可能受到中度损坏,产生倾斜及变形等,具有抗震设防能力的建筑物一般不会倒塌;地表变形梯度小于0.03的地段具有抗震设防能力的构建筑物一般只会受到轻度损伤或基本完好.     

汶川M_S8.0地震绵竹县汉旺镇周边地表破裂带展布方式及其震害意义

2008年5月12日汶川MS8.0地震的震中烈度为Ⅺ度,但位于地震烈度为Ⅹ度区边缘的绵竹县汉旺镇,无论是房屋毁坏情况还是遇难和失踪人员的数目,均高出周边地震烈度Ⅰ度,接近极震区的破坏程度。文中从汉旺镇周边地表地震破裂带展布方式的角度讨论了这种震害加重现象的原因,介绍了位于汉旺镇北面和南面出现的2条相距1.5km呈左阶斜列展布的地表破裂带。其中,位于汉旺镇北侧的地表破裂带,垂直位移1.4m,水平右旋位移0.44m;位于汉旺镇南侧的地表破裂带,垂直位移量由西向东递减,为3.0～0.2m。尽管这2条地表破裂带没有从汉旺镇中心通过,但汉旺镇正位于这2条地表破裂带夹持的左阶阶区,致使阶区内建筑物除遭受来自震源的振动外,又受到阶区内的挤压,由此加重了汉旺镇建筑物的破坏,也显示出地表破裂带对建筑物破坏形式的多样性。汉旺镇汶川MS8.0地震震害实例表明,地表破裂带的阶区,也是遭受地震时破坏加重的特殊构造部位     

2011年3月10日盈江5.8级地震Ⅷ度区烈度评定探讨

2011年3月10日,云南省德宏傣族景颇族自治州盈江县发生5 8级地震.宏观震中位于盈江县城盈江农场一带,与微观震中基本一致.调查发现,极灾区有房倒屋塌、地表开裂、喷砂冒水、工业构筑物破坏等现象.通过对这些震害现象的调查,根据《中国地震烈度表》( GB/T17742-2008)的相关判别指标,将本次地震最高烈度评定为Ⅷ...     

汶川地震震害与活动断层“避让带”宽度的分析研究

正2008年5月12日中国汶川发生里氏8.0级特大地震,沿地表可见活动断层无坚不摧的地震地表破裂与强烈的地震动使得地表破裂带沿线及其两侧近断层的建筑物遭受了毁灭性的破坏,同时,地震引发的大量山体滑坡、岩石崩塌、泥石流等次生地质灾害,加重了建筑物破     

汶川8.0级地震地表变形局部化样式与建筑物破坏特征关系初步研究

本文以汶川地震地表形变带的实地测量数据为基础,结合沿实测地震地表变形剖面建筑物破坏情况的调查与测量,分析了不同地震地表变形类型及其建筑物破坏特征,定量化地讨论了地表变形梯度与建筑物破坏程度间的关系。提出无论地震地表变形表现为何种类型的断层陡坎,地表破裂、强变形局部化在宽10~30m的地表破裂带内;建筑物受损情况最直接的影响是建筑物所处地点的地表变形梯度,地表变形梯度大于0.1的地段,建筑物均完全被摧毁;地表变形梯度在0.07~0.1间的地段,建筑物遭受严重损坏,产生倾斜及强烈变形等;地表变形梯度在0.03~0.07之间的地段,建筑物可能受到中度损坏,产生倾斜及变形等,具有抗震设防能力的构建筑物一般不会倒塌;地表变形梯度小于0.03的地段具有抗震设防能力的构建筑物一般只会受到轻的损坏或基本完好。     

古浪大震的地质灾害及破坏特征

根据野外调查和航片解译结果,对１９２７ 年古浪８ 级大震产生的主要地质灾害———地震破裂带、滑坡和裂缝及其展布特征进行了描述,并对该次地震的破坏特征及其控制因素进行了探讨．结果表明,古浪地震的地表破坏明显受地形和岩土类型的影响     

1918年南澳地震的破坏强度及震中位置

对１９１８年南澳地震的记录史料及有关文章进行了比较研究，并根据现场地震地质考察中发现的山体滑塌和地表破坏现象及其它宏观资料，重新圈定了这次地震的Ｘ度极震区，其形状为一北西向的长椭圆形，其内的北西向断裂带，应是该次地震的发震断裂。     

正演推算1730年北京西郊地震的发震断层和滑动角

通过设定一定的标准,对1730年发生在北京西郊61/2级地震的破坏记录进行数字化,得到地震在地表造成的实际破坏的定量分布图像;使用有限差分方法,计算出两条可能的发震断层--NE向的清河隐伏断层和NW向的东北旺-小汤山断裂在滑动角为0°和90°时,在地表产生的加速度的分布.通过将峰值加速度分布图像与实际破坏程度定量分布图像进行拟合,推算出了两条可能发震断层在这次地震中的作用(权重)及滑动角,从而判断出此次地震的主要发震断层是东北旺-小汤山断裂.为增加结果的可信度,文中还讨论了不同的地表破坏程度数据化模型对拟合结果的影响.     

A comparative study of bridge damage due to the Wenchuan, Northridge, Loma Prieta and San Fernando earthquakes

A comparative study of selected bridge damage due to the Wenchuan, Northridge, Loma Prieta and San Fernando earthquakes is described in this paper. Typical ground motion effects considered include large ground fault displacement, liquefaction, landslide, and strong ground shaking. Issues related to falling spans, inadequate detailing for structural ductility and complex bridge configurations are discussed within the context of the recent seismic design codes of China and the US. A significant lesson learned from the Great Wenchuan earthquake, far beyond the opportunities to improve the seismic design provisions for bridges, is articulated.     

隆尧地电阻率与地下水位关系分析

利用线性回归法,分析河北省隆尧地电阻率和地下水位的关系,发现该地区地电阻率季节性年变和近年来显著的趋势上升变化与地下水位动态变化相关.调查发现,年降雨量减小和农业用水量增大引起该区地下水位下降,从而导致地电阻率发生趋势上升变化.     

Passive microwave remote sensing of the historic February 2010 snowstorms in the Middle Atlantic region of the USA

The snowfall in the Baltimore/Washington metropolitan area during the winter of 2009/2010 was unprecedented and caused serious snow‐related disruptions. In February 2010, snowfall totals approached 2 m, and because maximum temperatures were consistently below normal, snow remained on the ground the entire month. One of the biggest contributing factors to the unusually severe winter weather in 2009/2010, throughout much of the middle latitudes, was the Arctic Oscillation. Unusually high pressure at high latitudes and low pressure at middle latitudes forced a persistent exchange of mass from north to south. In this investigation, a concerted effort was made to link remotely sensed falling snow observations to remotely sensed snow cover and snowpack observations in the Baltimore/Washington area. Specifically, the Advanced Microwave Scanning Radiometer onboard the Aqua satellite was used to assess snow water equivalent, and the Advanced Microwave Sounding Unit‐B and Microwave Humidity Sounder were employed to detect falling snow. Advanced Microwave Scanning Radiometer passive microwave signatures in this study are related to both snow on the ground and surface ice layers. In regard to falling snow, signatures indicative of snowfall can be observed in high frequency brightness temperatures of Advanced Microwave Sounding Unit‐B and Microwave Humidity Sounder. Indeed, retrievals show an increase in snow water equivalent after the detection of falling snow. Yet, this work also shows that falling snow intensity and/or the presence of liquid water clouds impacts the ability to reliably detect snow water equivalent. Moreover, changes in the condition of the snowpack, especially in the surface features, negatively affect retrieval performance. Copyright © 2011. This article is a U.S. Government work and is in the public domain in the USA.     

论西安地裂缝

西安地裂缝具定向延伸、多级羽列和成带、等距的分布格局,为水平左旋和南盘依次下落的同步位错。是基底断裂在统一区域应力场作用下,长期蠕动形成的隐伏微细裂缝,在地下水活动的附加作用下显现出来的一系列构造地裂缝。其发生方式为多点双向破裂,发生时间和活动高峰依次由南向北迁移。它们不均匀地蠕滑、时隐时现,有4、20、400和750年四种活动周期,可与渭河盆地的地震活动对应,是区域构造应力场加强的信息     

On the interpretation of recharge estimates from steady-state model calibrations

Ground water recharge is often estimated through the calibration of ground water flow models. We examine the nature of calibration errors by considering some simple mathematical and numerical calculations. From these calculations, we conclude that calibrating a steady-state ground water flow model to water level extremes yields estimates of recharge that have the same value as the time-varying recharge at the time the water levels are measured. These recharge values, however, are a subdued version of the actual transient recharge signal. In addition, calibrating a steady-state ground water flow model to data collected during periods of rising water levels will produce recharge values that underestimate the actual transient recharge. Similarly, calibrating during periods of falling water levels will overestimate the actual transient recharge. We also demonstrate that average water levels can be used to estimate the actual average recharge rate provided that water level data have been collected for a sufficient amount of time.     

Prediction of ground motion due to the collapse of a large-scale cooling tower under strong earthquakes

The ground motion owing to the collapse of a large-scale cooling tower under strong earthquakes was appropriately predicted using a comprehensive approach. The predicted results can be used for the safety evaluation of nuclear-related facilities adjacent to the cooling tower as well as in the planning of nuclear power plant construction in China. In this study, a cooling tower–soil model was first developed based on a falling weight–soil model, which the authors verified by falling weight tests. Then the collapse process of a cooling tower was simulated, and the collapse-induced ground vibrations were assessed by using the proposed model. Finally, the ground motion, which was a combination of the earthquake-induced ground motion and the collapse-induced ground vibrations, was estimated based on the superposition principle of waves. It was found that the cooling tower may collapse under strong earthquakes with the peak ground accelerations (PGAs) in the range of 0.35–0.45 g in x (EW) and y (NS) directions, respectively. These PGAs are far beyond the PGA range of major earthquakes in the common seismic design in China. The types of the site geologies of towers can significantly affect the collapse-induced ground vibrations. For a typical hard soil consisting of strongly weathered sandy slate, moderate ground vibrations may occur in the considered region. The collapse-induced PGAs were in the range of 0.017–0.046 g for the observed points at distances of 350 m in radial direction. For a rock-like foundation, the collapse-induced radial PGAs may be as high as 0.08 g at distances of 350 m, indicating that the effect of the collapse-induced ground vibrations on the nuclear-related facilities should be seriously assessed in certain scenarios.     

顺义地裂缝成因与顺义-良乡断裂北段第四纪活动性讨论

本文通过钻孔地层对比方法研究了顺义一良乡断裂北段的第四纪活动性，资料显示该断裂在第四纪期间呈现强弱交替的分期活动特征，距今315万年以来有3个较强活动期和3个较弱活动期，前三者分别距今266～315、171～228、73～147万年，后三者距今分别为228．266、147～171、0～73万年。中更新世晚期以来断裂活动不明显。超量开采地下水导致地面不均匀沉降是造成顺义地裂缝现今活动的主要原因。     

2021年日本福岛地震中建筑物破坏情况的现场考察报告

2021年2月13日23点07分（当地时间）日本福岛县海域发生了7.3级地震,这是2011年以来东日本大地震记录到的较大余震。距离震源较近的强震动观测点记录到约1.5 g的最大加速度。对离震源较近的几个城市及乡村,包括郡山市、福岛市和仙台市以内的地方进行了建筑物的震害调查。调查中发现:日本常用的木结构民宅在地震中仅发生了屋顶的瓦片掉落和剥离等轻微破坏,并没有发生严重的破坏。另外,在郡山市和福岛市有几栋高层钢筋混凝土结构的房屋有较严重的损坏。2021年福岛地震这一现象可能与地震动的短周期特性（小于1s）以及建筑物的高次振型有关。     

湖泊水体富营养化评价的改性灰色局势决策法

南四湖是我国主要的淡水湖泊之一,是山东省重要水源地。该地区自然资源条件优越,具有明显的区位优势,随着本地区能源基地的和社会经济高速发展。在水资源利用和煤炭资源开发中已产生或潜存很多环境问题,本文系统地综述了该地区存在的地下水位下降,水湖泊淤积,地面沉降与塌陷,水土流失和土壤盐渍化等一系列环境问题的状况,成因,发展,并针对性地提出了保护本地区水环境的基本策略。     

南四湖地区水环境问题探析

末次盛冰期（ＬＧＭ）是太阳辐射异常处于极低值,北半球第四纪冰流规模处于峰值,两万年来距人类环境最近但与现代气候有着巨大反差的特殊时期,７０年代以来由于新资料不断积累,气候模拟技术发展,海洋大陆冰流各圈层的相关和偶合,传统的气候指标和新的气候指标的认识和应用,以及区域性和全球性的国际合作,在ＬＧＭ古气候环境领域已经取得了巨大进展,本文根据数个国际ＬＧＭ合作计划研究成果,综述９０年代以来全球对ＬＧＭ研