Seismic behavior of breakwaters on complex ground by numerical tests: Liquefaction and post liquefaction ground settlements     

Linlin Gu  Feng Zhang  Xiaohua Bao  Zhenming Shi  Guanlin Ye  Xianzhang Ling 《地震工程与工程振动(英文版)》2018,17(2):325-342

A large number of breakwaters have been constructed along coasts to protect humans and infrastructures from tsunamis.There is a risk that foundation soils of these structures may liquefy,or partially liquefy during the earthquake preceding a tsunami,which would greatly reduce the structures’capacity to resist the tsunami.It is necessary to consider not only the soil’s liquefaction behavior due to earthquake motions but also its post-liquefaction behavior because this behavior will affect the breakwater’s capacity to resist an incoming tsunami.In this study,numerical tests based on a sophisticated constitutive model and a soil-water coupled finite element method are used to predict the mechanical behavior of breakwaters and the surrounding soils.Two real breakwaters subjected to two different seismic excitations are examined through numerical simulation.The simulation results show that,earthquakes affect not only the immediate behavior of breakwaters and the surrounding soils but also their long-term settlements due to post-earthquake consolidation.A soil profile with thick clayey layers beneath liquefied soil is more vulnerable to tsunami than a soil profile with only sandy layers.Therefore,quantitatively evaluating the seismic behavior of breakwaters and surrounding soils is important for the design of breakwater structures to resist tsunamis.  相似文献   

黑龙江嫩江地区三合屯金矿区糜棱岩锆石LA-ICP-MS U-Pb年龄与成矿的关系   总被引：1，自引：0，他引：1  

刘宝山  寇林林  张春鹏  李成禄  罗健  韩仁萍  李博文 《地质学报》2022,96(3):954-970

三合屯金矿位于黑龙江省嫩江县境内,普遍认为其是韧性剪切带型金矿.本次对采自韧性剪切带中花岗质糜棱岩样品进行了锆石LA-ICP-MS U-Pb定年,以约束剪切带的活动时代,并为金矿化事件提供依据,获得糜棱岩中热液锆石增生边加权平均年龄为162 Ma.因此,矿区在燕山期晚侏罗世经历剪切变形,并且这期变形事件与前人研究的科洛...  相似文献   

Analysis on the Characteristics of the Kalpin MS5.3 Earthquake Sequence of December 1, 2013 and Anomalies before the Earthquake     

Liu Jianming  Wang Qiong  Nie Xiaohong  Gao Ge  Zhang Linlin  Zhang Zhiguang  Xiang Yang 《中国地震研究》2017,31(3):381-394

This paper introduces the basic parameters, focal mechanism solutions and earthquake sequence characteristics of the Kalpin M_S5.3 earthquake sequence of December 1, 2013, and analyzed seismic activity before the earthquake, the adjacent tectonic features and the precursory anomaly at fixed points within a range of 200km. Research indicates:(1) The earthquake occurred on Kalpin fault, the source rupture type is thrust faulting with sinistral strike-slip component. (2) The earthquake sequence is mainshock-aftershock type, with the aftershock distribution attenuating quickly and trending NE. (3) Abnormal seismic activity before the earthquake was characterized by seismically nesting quiescence of M_S2.0-4.0 earthquakes, seismic quiescence of M_S4.0 earthquakes and seismic belts of M_S3.0 earthquakes in the Kalpin block, abnormal enhancement zone of moderate earthquakes on Puchang fault and seismological parameters. (4) Anomalies of precursory observation data at fixed stations are mainly characterized by mutation. Apart from the borehole tiltmeter in Halajun, the spatial distribution of other abnormal precursors showed a phenomenon of migration from the near field to far field and from the epicenter to the peripheries.  相似文献   

Temporo-spatial Characteristics of Swarm Distribution before Two MS6.0 Earthquakes in the Tianshan Area, China and Their Application to Earthquake Prediction     

Zhang Linlin  Ao Xueming 《中国地震研究》2017,31(3):395-402

The Nilka-Gongliu earthquake with M_S6.0 and Xinyuan-Hejing earthquake with M_S6. 6 successively occurred in Xinjiang on November 1,2011 and June 30,2012. Massive swarm activity was observed in a large area around the main shock epicenters before the two strong earthquakes. Main features are as follows:(1) The swarm activities not only increased significantly in number of earthquakes,but also presented a distinct swarm gap in spatial distribution,and the epicenters of the following strong earthquakes were all located in the swarm gap.(2) The duration of the swarm gap lasted longer,for 2-3 years.(3) The time-history characteristics of the swarms cumulative frequency indicates that swarm activity was quieter a few months before the main shocks. Finally,we discuss the results as well as the issues of their application in earthquake prediction.  相似文献   

Re-Os isotopic dating and geological significance of molybdenite from Xintian Cu-Mo polymetallic deposit in Yanbian,Jilin     

YIN Yue  CUI Bo  WANG Li  WANG Linlin  HUO Liang  LI Liang  DUAN Hongchang 《世界地质(英文版)》2018,(3)

Xintian polymetallic deposit is a hydrothermal vein type Cu-Mo deposit. Analysis on Re-Os isotopic dating for the molybdenite from this deposit is undertaken to determine metallogenic epoch and dynamics setting of the deposit. Re-Os isotopic dating for the molybdenite yields model ages ranging from 123. 9 ± 1. 9 Ma to 124. 7 ± 1. 8 Ma,with a weighted mean age of 123. 4 ± 0. 81 Ma,and an isochron age of 127 ± 16 Ma,MSWD= 0. 25,indicating that the metallization was at late Yanshanian. The content of Re in molybdenite is( 330. 1± 4. 0--367. 9 ± 3. 1) × 10~(-6),which demonstrates mantle derived metallogenic sources. Integrating the regional tectonic evolution and the metallogenic characteristics of other contemporaneous Cu-Mo deposits in the region,it is suggested that the Cu-Mo mineralization of this deposit occurred in an active epicontinental environment under lithospheric extension resulted from the subduction of the Izanagi plate to the Paleo-Asia continental margin at late Yanshanian. The Mantle wedge was partially melted with large amount of metallogenic elements dissolved in it. Under the favorable conditions of crust-mantle interaction,large-scale magmatic activity turns out to be the important mechanism of the mineralization of many Cu-Mo deposits in the Xiaoxingan Range--Zhangguangcai Mountain metallogenic belt,including the Xintian Cu-Mo polymetallic deposit.  相似文献   

Size distribution of individuals in the population of Asterias amurensis(Echinodermata: Asteroidea) and its reproductive cycle in China     

LI Baoquan  ZHOU Zhengquan  LI Bingjun  WANG Quanchao  LI Xiaojing  CHEN Linlin 《海洋学报(英文版)》2018,(6)

To obtain baseline information on the size distribution of individuals in the population and reproductive features of sea star Asterias amurensis, monthly surveys of the population were carried out from May to December 2010 and March to May 2015 in coastal waters off Yantai, China. Spawning period was predicted by gonad and pyloric caeca indices as well as anatomical and histological methods. In the A. amurensis population, both large individuals(143 mm) and small ones(42 mm) were present in all sampling months. The population size structure was driven by the appearance of big cohorts of individuals less than 55 mm from May to August. The appearance of small individuals in all months suggested a prolonged spawning period at other sites in this bay or sea stars growing slowly because of food shortage. An arm length is a good predictor to wet body weight for A.amurensis. The development of gonad was relative slow from May to September but rapidly reached a peak of20.95 in October 2010, and then dropped remarkably, indicating its spawning lasted from October to November.The same phenomenon was found from March to May 2015, suggesting another spawning during March to May,which was also verified by the results of histologic analysis on ovary. The gonad index(GI) and pyloric caeca index(PCI) tended to show a negative relationship. Due to the poor food availability, the reproductive characteristics of sea star were most likely affected by the shellfish mariculturein Yantai coastal waters.  相似文献   

浙江渔场修复振兴调查研究——以“一打三整治”专项执法行动为例          下载免费PDF全文

聂振林  水柏年  田阔  求锦津  张琳琳  韩晓凤  俞松立 《海洋开发与管理》2018,35(6):76-81

浙江渔场修复振兴暨"一打三整治"(依法打击涉渔"三无"船舶和违反伏休规定等违法生产经营行为,全面开展渔船"船证不符"整治、禁用渔具整治和污染海洋环境行为整治)专项执法行动实施以来,已取得显著成效,但也存在一些问题。文章基于调研所获资料,综合分析涉渔"三无"船舶回潮、部分伏休政策实施困难以及渔船"船证不符"、禁用渔具和海洋环境污染整治不彻底等问题及其原因,提出建立长效机制、加大整治力度和建立省内外联动机制的对策建议,为浙江省海洋生态修复、渔业资源保护和渔业可持续发展的相关决策提供参考。  相似文献   

Evaluation and spatiotemporal characteristics of glacier service value in the Qilian Mountains     

Sun  Meiping  Ma  Weiqian  Yao  Xiaojun  Zhao  Linlin  Li  Zhongqin  Qin  Dahe 《地理学报(英文版)》2020,30(8):1233-1248

Journal of Geographical Sciences - Glaciers provide essential resources and services for human well-being and so-cio-economic development in arid regions. It is of great significance for regional...  相似文献   

Coseismic deformation and slip distribution of the 1997 7.5 Manyi, Tibet, earthquake from InSAR measurements     

Hua Wang  Caijun Xu  Linlin Ge 《Journal of Geodynamics》2007,44(3-5):200-212

We use interferometric synthetic aperture radar (InSAR) observations to investigate the coseismic deformation and slip distribution of the 1997 M_w7.5 Manyi earthquake, a left-lateral strike-slip earthquake occurred on the west portion of the Kunlun fault in the northern Tibet, China. The fault trace is constrained by the combination of interferometric coherence image and azimuth offset image. The total length of the identified fault is about 170 km. We estimate the source parameters using a seven-segment fault model in a homogeneous elastic half-space. We first use a uniform slip model to estimate the slip, width, dip and rake for each segment, resulting in a maximum slip of 5.5 m with a depth of 11 km on the fourth segment. The average dip of the uniform slip model is about 93° northward and the average rake is about −2°. We then use a distributed slip model to estimate the pure strike-slip and oblique slip distribution, respectively. In the distributed slip model, the fault plane is discretized into 225 patches, each of them 4 km × 4 km. We fix the optimal geometric parameters and solve for the slip distribution using a bounded variable least-squares (BVLS) method. We find a geodetic moment of 1.91 × 10²⁰ Nm (M_w7.5), of which almost 68% released in the uppermost 8 km and 82% in the uppermost 12 km. For all the models used in this study, the synthetic profiles along strike show asymmetric displacements on the opposite sides of the fault, which are in agreement with the observations. This suggests that a linear elastic model with variable and non-vertical dips is also reasonable for the mechanism of the Manyi earthquake.  相似文献   

Multipath Mitigation of Continuous GPS Measurements Using an Adaptive Filter   总被引：13，自引：4，他引：9  

Linlin Ge  Shaowei Han  Chris Rizos 《GPS Solutions》2000,4(2):19-30

Though state-of-the-art dual-frequency receivers are employed in the continuous Global Positioning System (CGPS) arrays, the CGPS coordinate time series are typically very noisy due to the effects of atmospheric biases, multipath, receiver noise, and so on, with multipath generally being considered the major noise contributor. An adaptive finite-duration impulse response filter, based on a least-mean-square algorithm, has been developed to derive a relatively noise-free time series from the CGPS results. Furthermore, this algorithm is suitable for real-time applications. Numerical simulation studies indicate that the adaptive filters is a powerful signal decomposer, which can significantly mitigate multipath effects. By applying the filter to both pseudorange and carrier phase multipath sequences derived from some experimental GPS data, multipath models have been reliably derived. It is found that the best multipath mitigation strategy is forward filtering using data on two adjacent days, which reduces the standard deviations of the pseudorange multipath time series to about one fourth its magnitude before correction and to about half in the case of carrier phase. The filter has been successfully applied to the pseudorange multipath sequences derived from CGPS data. The benefit of this techniques is that the affected observable sequences can be corrected, and then these corrected observables can be used to improve the quality of the GPS coordinate results. ? 2000 John Wiley & Sons, Inc.  相似文献