城市居住区抗震防灾规划达标模糊评价

对城市居住区抗震防灾规划评价方法进行了研究,从防灾规划的角度定义居住区规划达标、基本达标和不达标的评语集和相应的含义,并且构建了包括建筑密度、人口密度、绿地率、用地适宜性、建筑物抗震能力、避震疏散条件六项指标的评价指标体系.在此基础上结合经验分析和模糊数学的方法确定各项指标的隶属函数,并用综合评价的方法和最大隶属度原则建立达标模糊评价模型.利用东营市的数据进行实例计算表明,该评价方法具有较好的区分度和实用性.     

无限弹性介质中隧道内爆炸动力响应的解析解

基于圆柱形薄壳结构理论,建立爆炸荷载作用下隧道结构的动力平衡方程.采用积分变换法求得Fourier变换域内爆炸荷栽作用下隧道位移场的积分表达式.结合具体算例,采用离散Fourier逆变换的数值计算方法,给出了爆心处隧道位移时程曲线、最大正应力时程曲线及某一时刻隧道位移幅值和最大正应力在x方向的变化曲线.其结果与数值计算结果相一致,验证了方法的可行性.     

黑石岭隧道围岩岩爆灾害的研究

地应力环境与围岩力学属性是隧道工程中引发岩爆的两大决定性因素。为了研究黑石岭隧道开挖过程中围岩岩爆灾害的潜在威胁及其表现规律,通过对岩爆里程段的现场采样、运用Kaiser效应法测量原岩应力和室内岩石力学实验,探讨了工程区内白云岩的岩性特征及其破坏规律,并基于强度理论和冲击能指标分析了发生岩爆的可能性及其发生方式。分析得知,该工程区内岩爆的潜在威胁较大,尤其是测点1和测点2处发生强岩爆的可能性最大,须在工程开挖过程中加强防治。     

河南平顶山平煤矿区天然地震、爆破、塌陷时频特征分析

选取2019年3月—8月河南平顶山市宝丰县平煤矿区发生的ML 2.0—2.9天然地震、爆破、塌陷等9次震动事件,在区域地质构造背景和波形特征分析基础上,采用短时傅里叶变换(STFT)方法开展时频波谱分析,提取不同类型事件的时频特征。结果显示:(1)天然地震频率成分丰富,且高、低频分布均匀,P波在约3 Hz和8 Hz处存在2个峰值,S波存在多个峰值;(2)爆破事件的时频谱相对集中,以低频为主,P波频率峰值约5Hz,信号主频随时间变化,大致呈线性降低至1—2 Hz;(3)塌陷事件频率成分以4 Hz以下的低频为主,P波无明显峰值且频率成分单一,主频出现在2 Hz左右的面波。本文结果可为今后该矿区震动事件类型判断提供参考依据。     

鹤岗地震台阵勘选记录信号及噪声的相关性分析

基于2019年中国地震局"一带一路"鹤岗地震台阵勘选资料,分析了勘选测点记录的近震Pg震相和远震P波震相在时间域和频率域的相关性。时间域相关分析结果显示,鹤岗地震台阵场地对近震Pg震相和远震P波震相的最佳监测距离分别约为550 m和1 570 m;频率域相干分析显示,监测远震P波信号的最佳距离约1 570 m,与时间域分析结果一致;近震和远震的最佳监测距离分别对应勘选台阵最内圆和最外圆半径,可作为该台阵布局设计的依据。台阵增益分析显示,勘选台阵对于Pg和P波震相识别具有一定增强作用。     

裂缝智能检测技术研究及其在埕岛潜山的应用

断裂(裂缝)对油气藏既有破坏又有保存作用。胜利埕岛奥陶系潜山油藏受裂缝控制,非均质性强,勘探目标预测难度大。本文以地震边缘检测为先验信息和启发因子,在自适应地震相干数据体上进行蚂蚁体追踪,精细检测裂缝,弥补了单一相干体检测分辨低的缺陷,获得了与钻井和实际地下情况吻合度更高的裂缝检测结果。对该区的油气勘探起到了指导作用。     

significance of high-resolution loess stratification based on grain size and magnetic susceptibility analysis to paleo-earthquake study: a case study of dongyugou loess section,at hongtong,shanxi province

As an important technology to paleoseismologic research, trenching has been used to identify paleo-earthquakes recorded in strata, combined with dating technology. However, there have been some bigger uncertainties and limitations. For instance, subtle strata in loess sediment cannot be interpreted only by naked-eye, which seriously affects identifying paleo-earthquake horizon and time. Therefore, how to improve the accuracy and reduce the uncertainty of paleo-earthquake identification is the important problem we are currently facing. Dongyugou loess section, located in the northeastern corner of Linfen Basin, Shanxi Province, cuts across the Huoshan piedmont fault. The section exposes not only the well-developed loess sequence, but also several obvious faulting events. Thus, this loess section is a better site to make a high resolution study to improve the accuracy and reduce the uncertainty of paleo-earthquake identification. Based on the high-resolution grain size and magnetic susceptibility analysis, and associated with visual interpretation by naked-eye, we made a high-resolution stratification of Dongyugou loess section, including high-resolution thickness of each stratum and its upper and bottom boundaries. Based on the high-resolution stratification and their comparison between two fault walls, we identified three earthquake events, which occurred after formation of u5-7, u4 and u2, corresponding to their stratification depth of 7.1m, 4.7m and 2.9m in hanging wall. Based on results of OSL dating and average sedimentation rate of hanging wall, we estimated that the three events occurred around 45.8ka(between (48.1±1.5)～(43.2±2.5)ka), 32.8ka(between (35.0±2.4)～(30.6±1.3)ka) and 23.3ka(between (26.4±0.8)～(20.9±0.7)ka). According to the thickness difference of three loess-paleosol sedimentary cycles between two fault walls, we calculated the coseismic vertical displacements of the three events as 0.5m, 0.4 and 1.3m, respectively. Compared with other segments of the Huoshan piedmont fault zone, we found the southernmost segment is the weakest, with longer recurrence interval of about 11ka and lower vertical slip rate of 0.048mm/a. The high-accuracy grain size and magnetic susceptibility analysis offers an effective method for reducing the uncertainties of the paleo-earthquake research in loess area.     

博斯腾湖水质现状(2010-2011年)及近50年来演变趋势

博斯腾湖(简称博湖)6个采样点周年(2010年6月-2011年6月)水质调查分析表明,博湖水质空间差异明显,但不同样点水质月变化无一致趋势.大湖区西北角水域水质最差;开都河入湖处水质月变化幅度大,水质相对较好;中东部水域水质处于中间水平.小湖区喇嘛湖水质最好,介于Ⅰ-Ⅲ级之间;北闸附近的湖沼湿地,水质差,多为Ⅴ类和劣Ⅴ...     

SEDIMENT PROPERTIES AND DYNAMICS IN THE TAIHU LAKE, CHINA

1 INTRODUCTION Large amounts of nutrients and contaminants such as trace metals are transported into large lakes frominflow rivers and then absorbed onto or associated with fine-grained sediment particles (Sheng and Lick,1979). The nutrients and contamina…     

河北省地倾斜观测资料干扰因素分析

在分析研究地倾斜观测资料时,为反映观测曲线的真实变化,需要剔除干扰因素的影响。该文通过整理分析河北省水平摆、垂直摆、水管仪等地倾斜观测资料,将河北省地倾斜干扰因素主要分为观测系统类干扰、观测环境类干扰以及气象因素类干扰。其干扰形态主要表现为变化趋势转折、变化速率改变、固体潮畸变、台阶、毛刺和突跳变化。