钢筋混凝土框架-剪力墙结构推覆分析

结合新建筑抗震设计规范的要求，采用自编的高层结构三维推覆分析程序(TBPOA)对某复杂体型的高层建筑框架剪力墙结构进行了三维推覆分析研究，对该结构进行了结构抗震整体性能和局部性能的评价。研究结果表明，满足小震强度设计要求并按构造要求配筋的钢筋混凝土柱，在大震作用时可能有部分构件难以满足变形要求，通过推覆分析对构件和结构的变形性能进行评估是很有必要的。     

Gravity wave breaking in easterly flow over Greenland and associated low level barrier- and reverse tip-jets

A first evidence of severe turbulence in the lower stratosphere during easterly tropospheric flow over Greenland is presented. A numerical simulation shows the turbulence to be associated with gravity wave breaking and that simulating with a horizontal resolution of 3 km gives substantially greater and more realistic turbulence than at a 9 km horizontal resolution. It is concluded that real-time simulations at high resolutions would improve aviation forecasts. As the atmospheric flow impinges on South-Greenland a barrier jet, a reverse tip jet and amplified mountain waves with secondary wave breaking are generated at the same time.     

Nature and timing of magma interactions before,during, and after the caldera-forming eruption of Volcán Ceboruco,Mexico

Volcán Ceboruco, Mexico, erupted ~1,000 years ago, producing the Jala pumice and forming a ~4-km-wide caldera. During that eruption, 2.8 to 3.5 km³ of rhyodacite (~70 wt% SiO₂) magma and 0.2 to 0.5 km³ of mixed dacite (~67 wt% SiO₂) magma were tapped and deposited as the Jala pumice. Subsequently, the caldera was partially filled by extrusion of the Dos Equis dome, a low-silica (~64 wt% SiO₂) dacite dome with a volume of ~1.3 km³. Petrographic evidence indicates that the Jala dacite and Dos Equis dacite originated largely through the mixing of three end-member magmas: (1) rhyodacite magma, (2) dacite magma, and (3) mafic magma. Linear least-squares modeling and detailed modal analysis indicate that the Jala dacite is predominantly a bimodal mixture of rhyodacite and dacite with a small additional mafic component, whereas the Dos Equis dacite is composed of mostly dacite mixed with subordinate amounts of rhyodacite and mafic magma. According to Fe–Ti oxide geothermometry, before the caldera-forming eruption the rhyodacite last equilibrated at ~865 °C, whereas the dacite was originally at ~890 °C but was heated to ~960 °C by intrusion of mafic magma as hot as ~1,030 °C. Zoning profiles in plagioclase and/or magnetite phenocrysts indicate that mixing between mafic and dacite magma occurred ~34–47 days prior to eruption, whereas subsequent mixing between rhyodacite and dacite magmas occurred only 1–4 days prior to eruption. Following the caldera-forming eruption, continued inputs of mafic magma led to effusion of the Dos Equis dome dacite. In this case, timing between mixing and eruption is estimated at ~93–185 days based on the thickness of plagioclase overgrowth rims.Editorial responsibility: T.L. Grove     

中国煤田测井技术发展历程及前景展望

煤田测井在确定煤层空间位置、研究沉积环境、解释煤岩力学性质、解决水文地质问题等方面具有独特的作用,是煤田地质很重要的一种勘探手段。通过回顾煤田测井技术及测井专业队伍50年的发展历程,展示煤田测井技术所取得的成绩和应用前景,以此纪念中国煤炭地质总局成立50周年。     

一种推广的互功率谱模态识别法及其在SHM问题中的应用

详细推导了多自由度结构多测点加速度响应的互功率谱模态矩阵展开式。进而给出了未知激励条件下基于各测点加速度响应互功率谱的频域多参考点模态识别法,同文献相比,该法适用于更广范围的激励条件。在频域平均法的辅助下,对ASCE SHM Benchmark问题的解析模型仿真加速度响应数据进行识别,结果表明该法有较好的识别精度,是一个有望应用于在线监测环境下的模态识别算法。     

阿尔金断裂带地壳和上地幔结构的P波层析成像

阿尔金断裂是青藏高原西北边缘最主要的断裂．天然地震P波层析成像结果揭示了阿尔金断裂（严格地说这里指阿尔金断裂中部,下同）为一条宽约40km左右的低速带,并以比较直立的产状向下延伸至150km左右深度．结果同时显示塔里木岩石圈曾经挤入到柴达木盆地下面,并受到后来发育起来的阿尔金断裂的切割．本次研究结果支持青藏高原中北部上地幔热物质参与了支撑高原高海拔地形的重力均衡作用的假设。     

利用gnss位移时空序列进行断层无震蠕滑特征分析

根据连续、 各向同性、 弹性半无限空间中有限矩形断层位错理论,模拟了断层不同蠕滑特征所引起的地表位移时空序列。通过对其进行主成分时空响应分析,得出了断层滑移类型及演化特征与地表位移主成分时空响应分布密切相关。大量实验研究表明,当断层滑移引起的地表位移大小至少与白噪声水平相当,为 有色噪声两倍时,通过地表位移主成分时空响应分析能够揭示断层滑移特征。由时间响应变化率可以判断断层滑移演化过程,由空间响应程度的梯度、 方向和大小可以判段断层分布和滑移方式。以2006年墨西哥格雷罗（ guerrero） 州慢地震事件为例,对分布于断层区域的 gnss台站位移时空序列进行了主成分变换和时空响应分析所得断层滑移特征与演化过程与有关学者的地球物理反演结果一致。     

An exploratory analysis of vegetation strategies to reduce shallow landslide activity on loess hillslopes,Northeast Qinghai-Tibet Plateau,China

Heavy summer rainfall induces significant soil erosion and shallow landslide activity on the loess hillslopes of the Xining Basin at the northeast margin of the Qinghai-Tibet Plateau. This study examines the mechanical effects of five native shrubs that can be used to reduce shallow landslide activity. We measured single root tensile resistance and shear resistance, root anatomical structure and direct shear and triaxial shear for soil without roots and five root- soil composite systems. Results show that Atriplex canescens (Pursh) Nutt. possessed the strongest roots, followed by Caragana korshinskii Kom., Zygophyllum xanthoxylon (Bunge) Maxim., Nitraria tangutorum Bobr. and Lycium chinense Mill. Single root strength and shear resistance relationships with root diameter are characterized by power or exponential relations, consistent with the Mohr- Coulomb law. Root mechanical strength reflects their anatomical structure, especially the percentage of phloem and xylem cells, and the degree and speed of periderm lignifications. The cohesion force of root- soil composite systems is notably higher than that of soil without roots, with increasing amplitudes of cohesion force for A. canescens, C. korshinskii, Z. xanthoxylon, N. tangutorum and L. chinense of 75.9%, 75.1%, 36.2%, 24.6% and 17.0 % respectively. When subjected to shear forces, the soil without root samples show much greater lateral deformation thanthe root-soil composite systems, reflecting the restraining effects of roots. Findings from this paper indicate that efforts to reduce shallow landslides in this region by enhancing root reinforcement will be achieved most effectively using A. canescens and C. korshinskii.     

考虑土-结构相互作用的高层建筑抗震分析

本文采用通用有限元程序ANSYS,针对上海地区一例土-箱基-高层建筑结构进行了三维有限元分析,计算中土体的本构模型采用等效线性模型,利用粘一弹性人工边界作为土体的侧向边界,并研究了土体边界位置、土性、基础埋深、基础形式以及上部结构刚度等参数对动力相互作用体系动力特性及地震反应的影响。     

NOAA Weather Radio (NWR) – A Coastal Solution to Tsunami Alert and Notification

The Washington State/Local Tsunami Work Group adopted the NOAA Weather Radio All-Hazards Warning System to warn citizens quickly and effectively of not only tsunami hazards but also other natural or man-made hazards. In concert with an array of deep ocean tsunami detectors, land-based seismic sensors, and warning messages issued by the tsunami warning centers, NWR provides a means to expeditiously get critical decision-making information to emergency managers, elected officials, and first responders. To implement the NWR strategy effectively, a partnership was developed to add a repeater to the NWR system to provide complete coverage to the coast of Washington and to shipping lanes off the coast. The Work Group also recognized the need to disseminate time critical hazard information on tsunamis to the public on beaches and in high traffic areas, so it developed a new notification system, with the first prototype installed on 2 July 2003 in Ocean Shores, Washington. A public education program also was developed to improve the impacted communities understanding of the tsunami hazard, the warning system, and actions they should take if a tsunami occurs.