Dynamic Method of Seismic Casualty Assessment

The concept of Initial Casualty Matrix is introduced. Using some probability distribution functions, the initial casualty matrix of masonry is determined. The dynamic method of seismic casualty assessment is established and then applied to the Tangshan earthquake data, with some conclusions drawn.     

超长灌注桩检测结果分析

本文通过四根超长大直径灌注桩单桩竖向承载力静载荷试验以及其它方法检测结果可知 ,超长桩承载力与使用反循环工艺、缩短成孔成桩时间、合理的泥浆性能、桩身混凝土完整性以及清渣彻底性有着密切相关。     

The character and reactivation history of the southern extension of the seismically active Clarendon–Linden Fault System, western New York State

Integration of 11 types of data sets enabled us to determine the location, character and fault history of the southern extension of the Clarendon–Linden Fault System (CLF) in southwestern New York State. The data sets utilized include detailed stratigraphic and fracture measurements at more than 1000 sites, soil gas anomalies, seismic reflection profiles, well logs and lineaments on air photos, topographic maps, Landsat and SLAR images. The seismically active CLF consists of as many as 10 parallel, segmented faults across the fault system. The fault segments are truncated by NW-striking cross-strike discontinuities (CSDs). The faults of the CLF and intersecting CSDs form fault blocks that have semi-independent subsidence and uplift histories. East-dipping reflectors in the Precambrian basement indicate the southward continuation of thrusts of the intra-Grenvillian Elzevir–Frontenac Boundary Zone. These thrusts were reactivated during Iapetan rifting as normal (listric) growth faults. In Ordovician Black River to Trenton time, the southern CLF segments experienced a second phase of growth fault activity, with faults displaying a cumulative stratigraphic throw of as much as 170 m. Thrusting on the same east-dipping Precambrian reflectors typified the CLF in Taconic (post-Trenton) times. Detailed comparisons among the fault segments show that the fault activity in Silurian and Devonian times generally alternated between the western and central main faults. In Late Devonian time, the fault motion reversed from down-on-the-east to down-on-the-west about the time the Appalachian Basin axis passed across the CLF in its westward migration. The deep Precambrian faults of the CLF were thus reactivated as the Appalachian Basin developed in Acadian times. Finally, the CLF thrust fault imaged on seismic line CLF-1 offsets all bedrock (Devonian) units; thus, significant motion occurred along this fault during Late Acadian, or more likely, Alleghanian time.     

论采矿权的物权特征

物权是现代社会经济生活中极为重要的权利。运用物权原理论述了采矿权作为财产性权利所具有的他物权、排他性、不动产权、用益物权特征,并阐述了采矿权与矿产资源国家所有权的关系,分析了采矿权物权特征在我国采矿权法律制度中的重要作用。     

Cyclic liquefaction screening of sand with non-plastic fines:Critical state approach

There have been significant advances in the application of critical state,CS,in liquefaction potential assessment.This was done by comparing state parameter,j with estimated characteristic cyclic stress ratio,CSR due to an earthquake.A cyclic resistance ratio,CRR curve,which can be determined from cyclic liquefaction tests,separates historical liquefied and non-liquefied data points(j,CSR).On the other hand,the concepts of equivalent granular state parameter,j*,which was developed for sands with fines,can be used in lieu j to provide a unifying framework for characterizing the undrained response of sands with non/low plasticity fines,irrespective of fines content(fc).The present work combines these two propositions,and by merely substituting j*for j into the aforementioned CS approach to capture the influence of fc.A series of static and cyclic triaxial tests were conducted,separately and independently of the concept of j*,for sand with up to fc of 30%.The clean sand was collected from Sabarmati river belt at Ahmedabad city in India which was severely affected during the Bhuj earthquake,2001.The experimental data gave a single relation for CRR and j*which was then used to assess liquefaction potential for a SPT based case study,where fc varies along the depth.The prediction matched with the field observation.     

地震仪表系统中电磁干扰识别与排除方法研究

针对地震仪表系统受电磁干扰易发生误报警的情况,提出运用有限状态机来实现电磁干扰识别及排除。运用该方法 可有效地降低系统的误报警率,提高系统的可靠性。     

Seasonal-scale nearshore morphological evolution: Field observations and numerical modeling

A coupled waves–currents-bathymetric evolution model (DELFT-3D) is compared with field measurements to test hypotheses regarding the processes responsible for alongshore varying nearshore morphological changes at seasonal time scales. A 2001 field experiment, along the beaches adjacent to Grays Harbor, Washington, USA, captured the transition between the high-energy erosive conditions of winter and the low-energy beach-building conditions typical of summer. The experiment documented shoreline progradation on the order of 10–20 m and on average approximately 70 m of onshore sandbar migration during a four-month period. Significant alongshore variability was observed in the morphological response of the sandbar over a 4 km reach of coast with sandbar movement ranging from 20 m of offshore migration to over 175 m of onshore bar migration, the largest seasonal-scale onshore migration event observed in a natural setting. Both observations and model results suggest that, in the case investigated here, alongshore variations in initial bathymetry are primarily responsible for the observed alongshore variable morphological changes. Alongshore varying incident hydrodynamic forcing, occasionally significant in this region due to a tidal inlet and associated ebb-tidal delta, was relatively minor during the study period and appears to play an insignificant role in the observed alongshore variability in sandbar behavior at kilometer-scale. The role of fully three-dimensional cell circulation patterns in explaining the observed morphological variability also appears to be minor, at least in the case investigated here.     

Second-order state transition for relative motion near perturbed,elliptic orbits

This paper develops a tensor and its inverse, for the analytical propagation of the position and velocity of a satellite, with respect to another, in an eccentric orbit. The tensor is useful for relative motion analysis where the separation distance between the two satellites is large. The use of nonsingular elements in the formulation ensures uniform validity even when the reference orbit is circular. Furthermore, when coupled with state transition matrices from existing works that account for perturbations due to Earth oblateness effects, its use can very accurately propagate relative states when oblateness effects and second-order nonlinearities from the differential gravitational field are of the same order of magnitude. The effectiveness of the tensor is illustrated with various examples.     

POSTFIRE SUCCESSION IN AN ADIRONDACK FOREST*

ABSTRACT. Landscape diversity has increased with the surprising postfire establishment of aspen at upper elevations (700–945 meters above sea level) in the High Peaks of Adirondack Park in upstate New York. Tree seedlings returned quickly to the charred slopes west of Noonmark Mountain after an accidental fire consumed the forest in 1999. Aspen stands have replaced the spruce‐fir‐birch forests in the burned area even though mountain paper birch is expected to colonize burned sites at these elevations. Environmental conditions, historical events, and unique circumstances help explain why quaking aspen and bigtooth aspen rather than paper birch blanket the burned mountainside. Climate change over the past century to warmer, wetter conditions may have fostered this marked shift in species composition. In the unburned firebreak that people cleared to contain the flames, pin cherry has regenerated from seeds stored in the soil for nearly a century. The history of pin cherry on the site suggests that large fires or severe windthrow may have been more common in the region than was previously documented.     

三维地学模拟几个方面的研究现状与发展趋势

对三维地学模拟中的三维空间数据模型,三维地学模拟技术以及三维地学模拟软件的应用３个方面的研究现状进行了总结,并指出了发展趋势与研究思路。