Experimental study on the effects of artificial bed roughness on turbidity currents over abrupt bed slope change

A series of experimental observations are presented in the current study to discuss the effects of artificial bed roughness on the turbidity current flowing in a rectangular channel with an abrupt change in bed slope.For this purpose,two different types of elements,sinusoidal and trapezoidal,with various heights and arrangements are considered as artificial bed roughness.A Vectrino velocity meter was used to measure the velocity and sediment concentration profiles.The effects of inlet sediment concentration on front velocity,body velocity,unit discharge,sediment concentration,and suspended load transport rate also were investigated.Accurate equations were developed for estimation of the velocity of a turbidity current over smooth and rough beds.The unexpected experimental results showed that unlike the effect of roughness height,a change in the roughness arrangement has no significant influence on the velocity of a turbidity current.Also,the effect of bed roughness on the front velocity of a denser current is more significant.     

地面-坑道激电测深方法在山东玲珑断裂带深部找矿中的应用

在山东玲珑断裂带深部找矿中,考虑断裂带处在地电干扰和地形变化复杂地段,且深部地质体产状变化较大,仅依据半空间地面物探方法很难摸清地质体的展布形态,盲目布设钻孔会造成找矿成本的提高。为精确反演深部矿体的边界范围、走向及倾向,提高钻孔见矿率,降低找矿成本,在山东玲珑断裂带地面、坑道采用立体物探技术,试验通过布设多条方位不同的地-坑、坑-坑和地-地纵横激电中梯剖面和双向三极测深剖面,进行了二维电法剖面反演。在地面-坑道激电测深方法中,地面-坑道供电,坑道测量探测深度与坑道深度呈正相关,反映了深部巷道底板以下电阻率和极化率的分布状况,可以实现深地探测目的。由于地面-坑道供电,坑道测量装置处在半空间和全空间两个部分,需要采用"镜像法"和地下倾斜偶极源电流场特征对其装置系数k值重新推导,以反映坑道空间岩矿体真实电阻率的变化。坑道中梯剖面异常与单向三极剖面异常、双向三极电测深反演结果对应较好。经钻探验证,矿体分布与物探推断高极化体基本一致,为快速准确布设深部钻孔提供资料。     

1994年9月16日台湾浅滩7.3级地震发震构造的讨论

从台湾海峡与台湾浅滩的地貌特征、区域构造格局、海峡盆地形成历史、深部构造与断裂构造、震源机制解以及地震活动等方面论述了台湾浅滩７．３级地震的发震构造,认为北东东向澎湖—北港隆起南侧断裂（义竹断裂）是该地震的发震构造。     

德州深层地下水降落漏斗相关模型建立及其应用

德州市深层地下水,由于长期大量开采,早已形成降落漏斗。作者从漏斗条件的实际出发,利用１７年的地下水动态观测资料,在地下水资源均衡基础上,进行相关分析,建立了相关模型。利用相关模型直接进行不同开采条件下的地下水位预报和限定地下水位条件下的开采量计算。此外,还利用相关模型进行了含水层（组）弹性释水系数和漏斗补给量计算。     

油气成藏流体动力系统分析原理及应用

阐述了油气成藏流体动力系统分析的基本原理,把油气成藏流体动力系统分为重力驱动型、压实驱动型、滞流型和封存型四种类型。结合国内外的研究实例,分析了不同类型流体动力系统油气藏形成和分布的规律,强调在不同类型的流体动力系统中,油气藏形成的机理不同,在成藏动力学研究中有不同的侧重点。加强重力驱动型和封存型流体动力系统动力系统油气成藏条件研究对我国南方海相盆地和其它勘探程度较高的盆地深部的油气勘探具有重要意义。     

火山活动与沉积盆地的形成和演化

我国大陆地壳进入中生代以来,发生了较其他陆壳更为强烈的构造运动,印支,燕山,喜马拉雅运动都是发生在我国大陆地壳以裂陷作用为主的典型运动,在中生代板块构造的特定时代和以裂陷作用主主的构造运动作用下,岩浆活动沿断穿骨石圈和地壳的深断裂发生,上涌至地壳地面形成火山岩带和地层格架中的火山岩层,上涌至地壳内部形成壳内流体相央浆房而成为高导层,火山活动是由中生代生成的太平洋板块和我国大陆地壳俯冲,使大陆地壳深     

二连断陷盆地群伸展构造系统及其发育的深部背景

二连盆地形成于侏罗纪到早白垩世期间,是东北亚断陷盆地系内的一个典型的盆岭式断陷盆地群,其内蕴藏丰富的煤和油气资源,综合分析了二连盆地油气勘探中积累的地质资料,系统地研究了与盆地形成有关的构造,并与北美西部盆岭省进行了对比,揭示了二连盆地宽裂陷作用和低拉伸率条件下的伸展构造系统。以上述研究和前人的研究成果为基础,探讨了盆地发育的深部背景。     

深埋隧道工程主要灾害地质问题分析

深埋隧道工程由于埋深大、洞程长、地质条件复杂,在修筑过程中,将会发生一系列特殊的灾害地质问题。如：高压涌水、高地应力及岩爆、高地温问题等。本文根据大量深埋隧道工程实例,分析服这些灾害地质问题发生条件和影响因素。     

Development of Seismic Risk Scenarios Based on a Hybrid Method of Vulnerability Assessment

A hybrid methodology of vulnerability analysis is presented, involving elements from both empirical and theoretical methods. A model for correlating analytically calculated structural damage indices to loss (in monetary terms) is also proposed and calibrated against available statistical data. Probability damage matrices derived using this methodology are incorporated into a cost-benefit model tailored to the problem of estimating the feasibility of seismically rehabilitating the existing stock of reinforced concrete buildings in Thessaloniki, Greece. Losses calculated using the suggested procedure are found to be in good agreement with losses incurred during the 1978 Thessaloniki earthquake. The results of the present study also indicate that benefit/cost ratios for reinforced concrete buildings are quite low. Hence, it appears that a pre-earthquake strengthening programme is not economically justifiable.     

Seismic Zoning of Croatia

The territory of Croatia and neighboring regions is divided into 17 seismic source zones, considering available seismological and geological data. On this basis, seismic hazard elements (seismicity rate, maximum magnitude, b-value, probabilities of exceedance and return periods for a predefined set of magnitudes) are computed using the maximum likelihood method appropriate for treating data-sets with variable completeness thresholds. The values of long term expected peak horizontal acceleration obtained by using a combination of the deterministic and the probabilistic procedure are the highest in the Dubrovnik zone, while the Zagreb zone has the highest earthquake hazard in the continental part of the country. This revised version was published online in June 2006 with corrections to the Cover Date.