A new high-stress undrained ring-shear apparatus and its application to the 1792 Unzen–Mayuyama megaslide in Japan     

Kyoji Sassa  Khang Dang  Bin He  Kaoru Takara  Kimio Inoue  Osamu Nagai 《Landslides》2014,11(5):827-842

Sassa and others in the Disaster Prevention Research Institute (DPRI), Kyoto University, developed a series of undrained ring-shear apparatus to physically simulate landslide initiation and motion, from DPRI-3 (Sassa 1992) to DPRI-7 (Sassa et al., Landslides 1(1):7–19, 2004). The maximum undrained capacities in the DPRI series ranged from 300 to 650 kPa. Sassa and others in the International Consortium on Landslides (ICL) have developed a new series of undrained ring-shear apparatus (ICL-1and ICL-2) for two projects of the International Programme on Landslides (IPL-161 and IPL-175). Both projects are supported by the Science and Technology Research Partnership for Sustainable Development Program (SATREPS) of Japan. ICL-1 was developed to create a compact and transportable apparatus for practical use in Croatia; one set was donated to Croatia in 2012. ICL-2 was developed in 2012–2013 to simulate the initiation and motion of megaslides of more than 100 m in thickness. The successful undrained capacity of ICL-2 is 3 MPa. This apparatus was applied to simulate possible conditions for the initiation and motion of the 1792 Unzen–Mayuyama megaslide (volume, 3.4?×?10⁸ m³; maximum depth, 400 m) triggered by an earthquake. The megaslide and resulting tsunami killed about 15,000 people. The Unzen Restoration Office of the Ministry of Land, Infrastructure and Transport (MLIT) of Japan systematically collected various papers and reports and published two summary leaflets: one in English in 2002 and an extended version in Japanese in 2003. Samples were taken from the source area (for initiation) and the moving area (for motion). The hazard area was estimated by the integrated landslide simulation model LS-RAPID, using parameters obtained with the ICL-2 undrained ring-shear apparatus. The estimated hazard area agrees reasonably with the landslide moving area reported in the Ministry leaflets.  相似文献   

汶川地震基岩同震断层泥结构特征   总被引：5，自引：0，他引：5       下载免费PDF全文

韩亮  周永胜  陈建业  马胜利  杨晓松  何昌荣  党嘉祥 《第四纪研究》2010,30(4)

汶川Ms8.0地震形成的地表破裂带主要沿松散沉积层分布,但在北川-映秀地表破裂带中,发现5处同震地表破裂带穿过基岩.通过详细介绍其中的4处基岩同震断层剖面,给出基岩同震断层泥的特点和识别标志.断层剖面位置从北向南:平武平溪、北川擂鼓、安县肖家桥和虹口八角庙.同震断层主要出露在相对较软的基岩中,断层长期活动形成了分带性特征显著的断层变形带,主要包括构造角砾岩、断层角砾、老断层泥和最新断层泥.其中,同震滑动产生的最新断层泥最为松软,厚度最薄,颜色最深,内部几乎不含角砾并与其他部分接触边界清晰平直.基岩同震断层泥的结构特征与断层围岩性质密切相关,当同震断层上下盘围岩由多种岩石组成,而且上下盘围岩强度差别较大时,断层变形带结构相对复杂,发育有厚层断层泥,局部存在多个滑动面;当上下盘围岩岩石组成相对单一时,断层变形带结构相对简单,断层泥厚度较薄.在野外断层变形带结构划分基础上,对部分断层剖面中的同震断层泥和断层岩进行了初步的显微结构分析,给出断层蠕滑和粘滑的显微结构特征,对同震断层泥中的流体活动方式进行了讨论.  相似文献   

从北华北盆地的地质结构看1976年唐山地震的发震机理     

杨克绳  胡平  党晓春 《地学前缘》2010,17(5):263

北华北盆地经过古近纪拉张、新近纪挤压形成了怀柔—三河—唐山—锦州—下辽河向南突出的弧形构造带,它与向南推挤的南北向唐山—丰南隆起一起构成燕辽山字型构造。唐山—丰南脊柱向南推挤造成弧顶挤压应力集中。一旦应力集中超过极限值,应力必然释放,形成大地震。文章从这一认识出发对1976年唐山地震的发震机理进行了探讨。  相似文献   

自动气象站现场校准和传感器调整方法探讨   总被引：11，自引：6，他引：5  

党选发  李晓峰  袁志鹏 《气象科技》2007,35(3):432-434

讨论在自动气象站现场校准中一些需要改进的校准方法和超差传感器的调整方法。在将近2年对74个自动气象站的温湿度传感器、风向风速传感器、气压传感器、雨量和蒸发传感器的现场校准中,不断改进校准方法,对超差传感器进行调整。结果表明:气温传感器和风向传感器的校准方法需要改进,湿度传感器、气压传感器、雨量和蒸发传感器超差时可进行适当调整,使传感器误差值达到最小。  相似文献   

内蒙白音华一号露天煤矿首采区南(非工作)帮边坡稳定性评价     

刘大野  陈立云  党广民 《中国煤炭地质》2010,(7):41-47

根据工程地质勘察成果,分析了首采区南(非工作)帮边坡岩体的工程地质条件,并据此进行了岩石物理力学性质统计,软弱层(面)分布特征以及泥岩、炭质泥岩对地下水敏感度等研究。在此基础上建立了不同条件下不同滑面类型的边坡极限平衡法数值分析模型,并进行了相应的边坡稳定性计算成果评价,由此提出了南(非工作)帮边坡角的建议值:次边坡角采用值α1≤13°,主边坡角采用值α2≤19°。根据评价结果提出了修正岩体力学参数、合理调整采区和留设安全煤壁的建议。该评价结果为露天煤矿总平面设计系统中的边坡设计提供了依据。  相似文献   

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陈俊勇  党亚明  程鹏飞 《大地测量与地球动力学》2007,27(5):1-4

?????????????????(GNSS)???GPS??????????????GLONASS???????GALILEO?????????????;????????μ?????????????????????????????????·??Ч??????????????????????????λ?????仯????????λ??????????????????λ????????;??????GPS???????λ(PPP)???????  相似文献   

滩间山金矿矿床成因初步探讨     

党兴彦  付宝侠 《青海国土经略》1996,(2)

本文通过对滩间山矿区地层、构造及岩浆岩与成矿关系的研究,认为中元古界万洞沟群是金的矿源层;成矿构造具有多期次、多阶段活动的特点,矿体受单一及复合型式的构造控制;华力西期侵入体对成矿作用仅体现于为矿床的形成与再造提供热源。矿质在弱酸—中偏碱性溶液中,主要呈硫络合物的形式搬运、并在还原条件下成矿。特别指出,含磷质物地层是区内重要的岩金找矿标志之一。  相似文献   

The application of δ¹³C and C/N ratios as indicators of organic carbon sources and paleoenvironmental change of the mangrove ecosystem from Ba Lat Estuary, Red River, Vietnam     

Nguyen Tai Tue  Hideki Hamaoka  Atsushi Sogabe  Tran Dang Quy  Mai Trong Nhuan  Koji Omori 《Environmental Earth Sciences》2011,64(5):1475-1486

In this study, two sediment cores (~70 cm) were collected from separate mangrove forests straddling the Ba Lat Estuary, Red River of northern Vietnam, to examine the origins of sedimentary organic carbon (SOC) and reconstruct the paleoenvironment. In addition, mangrove leaves and particulate organic matter were collected and measured for δ¹³C to trace the origins of SOC. The cores were analyzed by high-resolution sections for δ¹³C, TOC, C/N ratios, sediment grain size, water content, and porosity, with values of δ¹³C, TOC, and C/N ratios ranging from −28.19 to −22.5‰, 2.14–30.94 mg/g, and 10.29–18.32, respectively. The δ¹³C and TOC relationship indicated that there were some small residual effects of diagenetic processes on TOC and δ¹³C values in mangrove sediments. However, the shifts of δ¹³C and C/N ratios from the bottom to the surface sediment of the cores explained the change in organic matter sources, with values of C/N > 12 and δ¹³C < −25‰, and C/N < 12 and δ¹³C > −25‰ indicated terrestrial (e.g., mangrove litter) and marine phytoplankton sources, respectively. The covarying δ¹³C, C/N ratios, and sediment grain sizes during the past 100 years in sediment cores showed that the paleoenvironment may be reconstructed into three environments (subtidal, tidal flat, and intertidal mangrove). General trends in δ¹³C and C/N followed a gradual increase in the C/N ratio and a concomitant decrease in δ¹³C from the subtidal, through to tidal flat, and to the intertidal mangrove. δ¹³C and C/N ratios are therefore effective in measuring the continuum of environmental change in mangrove ecosystem.  相似文献   

Underground water stress release models     

Yong Li  Shenjun Dang  Shaochuan Lu 《地震学报(英文版)》2011,(4):335-341

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Structural controls on the occurrence and morphology of karstified assemblages in northeastern Vietnam: a regional perspective     

Hai Thanh Tran  Bat Van Dang  Chi Kim Ngo  Que Dinh Hoang  Quyen Minh Nguyen 《Environmental Earth Sciences》2013,70(2):511-520

Karstified assemblages occur widely in, and distinctively shape, the geological landscape of the northeastern part of Vietnam. These carbonate rocks were deposited during three major periods of basinal evolution including: (1) Late Cambrian, (2) Early Devonian to Early Carboniferous, and (3) Carboniferous to Earliest Triassic. These sedimentary units contain primary sedimentary structures and have undergone numerous post-depositional geological processes including multiple deformational events, which can be regionally correlated. Several thrusting events and associated folding have led to significant thickening of the carbonate units. The subsequent post-thrusting cross-folding events, followed by several phases of brittle faulting and fracturing further modified the spatial geometry and outcrop of these rocks. The combination and interaction of the primary structures with those formed during the long-lived and complicated deformational history is an important controlling factor in local and regional hydrogeological systems in the region. The geological structures now recorded in the carbonate units ultimately govern the formation of the unique modern surface and sub-surface geomorphology of the karstic terrains in northeastern Vietnam. These structures should be further investigated in the context of water resource assessment and natural hazard prediction and mitigation.  相似文献