吉林台爆破料应力应变关系的三轴试验研究

通过室内大型三轴实验，研究了吉林台水库爆破料在不同级配下的应力应变关系，得到了在一定击实功下爆破料的最大干密度随细料含量变化的规律，分析了爆破料在不同级配和不同围压下应力与应变的变化规律、轴向应变与体积应变的关系及抗剪强度变化特性．从微观的角度说明了变化规律产生的原因，得出爆破料的抗剪强度随级配的变化而变化的规律．     

单一滑面边坡的非稳定蠕变模型分析

对单一滑面边坡的非稳定蠕变分析是边坡稳定性研究的基础。文中对岩质边坡单一滑面的流变变形机制进行了分析，提出了一种能较好反映这一变形机制的非稳定蠕变模型。特别是描述单一滑面边坡的非稳定蠕变破坏阶段，并对其稳定性进行了讨论。结合一些工程实例进行了对比验证，为滑坡灾害的预测和防治提供依据。     

构造煤与原生结构煤的显微傅立叶红外光谱特征对比研究

通过对平顶山、郑州和南票三大矿区石炭二叠纪含煤岩系中高煤级烟煤和无烟煤的显微傅立叶红外光谱分析，探讨了原生结构煤与构造煤的有机大分子结构演化特征及其影响因素。结果表明，构造应力有利于煤中氢发生化学环境转移，使脂肪烃含量相对减少、稳定的芳香烃含量相对增加，促进煤大分子结构缩合度和有序度增加。     

某大厦深基坑开挖与施工安全监测实践与体会

从深基坑安全监测实例出发,介绍了一种简便、易行、稳定、可靠的射线形水平位移基准网,同时适用用小角法高精度位移监测.另外就温度的变化对水平位移值的影响,降水施工对地面沉降,深层土体位移的影响及测斜管埋设的重要性提出了自己的观点、认识与体会,希望对类似工程有一定参考价值.     

Spectral Filtering and Classification of Terrestrial Laser Scanner Point Clouds

A method is presented for filtering and classification of terrestrial laser scanner point clouds. The algorithm exploits the four-channel (blue, green, red and near infrared) multispectral imaging capability of some terrestrial scanners using supervised, parametric classification to assign thematic class labels to all scan cloud points. Its principal advantage is that it is a completely data-driven algorithm and is independent of spatial sampling resolution since the processing is performed in four-dimensional spectral feature space. Its application to two data-sets of different spatial extent and spatial and spectral complexity is reported, for which respective overall classification accuracies of 87·0% and 82·0% were achieved. Analysis of the input data with emphasis on the characteristics pertinent to the anticipated outcomes precedes detailed analysis of the classification results and error sources and their causes. Erroneously classified points are attributed to radiometric errors stemming from both detector hardware and physical effects.     

时间序列转折突变点检测的线性函数方法

根据转折突变的定义，在引入线性半截多项式的前提下，提出检测时间序列转折突变点的一种新方法。此方法不仅能找出时间序列中存在的多个转折突变点，而且使得检测到的突变点通过统计显著性检验。应用此方法对北半球1851—1990年年平均气温距平及其11年滑动平均序列，1901—1999年昆明5月降水及其11年滑动平均的降水序列分别进行了检测。发现北半球年平均气温距平在1879、1889、1939和1973年附近出现了年际转折突变，在1878、1888和1941年以及1972年出现了年代际尺度的转折突变；昆明5月雨量不存在年际转折突变点，但昆明5月雨量在1918、1966以及1978年附近出现了年代际尺度转折突变。     

青藏公路路基变形分析

为研究青藏公路多年冻土人为上限在退化过程中对路基变形产生的影响过程和程度, 在唐古拉山以南选择了3处具有代表性的路面进行了为期2 a的路面变形观测. 资料表明, 在多年冻土人为上限退化过程中随着公路路基结构、冻土类型的不同, 路基变形从冻胀和融沉过程、冻胀量和融沉量、发生的时间都有很大的不同. 在高含冰量多年冻土区采用半挖半填结构产生的路基变形最为剧烈, 在含冰量相对少且采用较高路堤结构的地段路基变形过程相对平缓. 同时结合探地雷达的勘察结果对路基下的融化区、多年冻土区的内部结构进行了分析. 结果显示,多年冻土人为上限的下移、地下冰的融化会在多年冻土人为上限以上的地质体中导致较强烈的层间错动和扰动.     

An experimental study of grain scale melt segregation mechanisms in two common crustal rock types

Creation of pathways for melt to migrate from its source is the necessary first step for transport of magma to the upper crust. To test the role of different dehydration‐melting reactions in the development of permeability during partial melting and deformation in the crust, we experimentally deformed two common crustal rock types. A muscovite‐biotite metapelite and a biotite gneiss were deformed at conditions below, at and above their fluid‐absent solidus. For the metapelite, temperatures ranged between 650 and 800 °C at P_c=700 MPa to investigate the muscovite‐dehydration melting reaction. For the biotite gneiss, temperatures ranged between 850 and 950 °C at P_c=1000 MPa to explore biotite dehydration‐melting under lower crustal conditions. Deformation for both sets of experiments was performed at the same strain rate (ε.) 1.37×10^?5 s^?1. In the presence of deformation, the positive ΔV and associated high dilational strain of the muscovite dehydration‐melting reaction produces an increase in melt pore pressure with partial melting of the metapelite. In contrast, the biotite dehydration‐melting reaction is not associated with a large dilational strain and during deformation and partial melting of the biotite gneiss melt pore pressure builds more gradually. Due to the different rates in pore pressure increase, melt‐enhanced deformation microstructures reflect the different dehydration melting reactions themselves. Permeability development in the two rocks differs because grain boundaries control melt distribution to a greater extent in the gneiss. Muscovite‐dehydration melting may develop melt pathways at low melt fractions due to a larger volume of melt, in comparison with biotite‐dehydration melting, generated at the solidus. This may be a viable physical mechanism in which rapid melt segregation from a metapelitic source rock can occur. Alternatively, the results from the gneiss experiments suggest continual draining of biotite‐derived magma from the lower crust with melt migration paths controlled by structural anisotropies in the protolith.     

Ground deformation of the southern sector of the Aeolian islands volcanic arc from geodetic data

The deformation pattern and the dynamics of the southern sector of the Aeolian archipelago are investigated. A study on the ground deformation, measured over the last 20 years in the trilateration geodetic network between the islands of Vulcano and Lipari, has been conducted. Analysis of the relative displacements and the uniform strain tensor parameters, as well as the comparison between areal dilatation and the vertical variations deduced by precise levelling, allow distinguishing different phases associated both with the regional dynamics and the local volcanic context of the area. These phases, however, appear to be closely interrelated. The analysis of the deformation pattern allows to constrain the predominance of a roughly E–W trending extension and a N–S contraction at a regional scale. This regime is consistent with right-lateral movements along a NW–SE striking fault system.     

Paleoliquefaction study of the Clarendon–Linden fault system, western New York State

The lack of earthquake-induced liquefaction features in Late Wisconsin and Holocene sediments in Genesee, Wyoming, and Allegany Counties suggests that the Clarendon–Linden fault system (CLF) did not generate large, moment magnitude, M≥6 earthquakes during the past 12,000 years. Given that it was the likely source of the 1929 M 4.9 Attica earthquake, however, the Clarenden–Linden fault system probably is capable of producing future M5 events. During this study, we reviewed newspaper accounts of the 1929 Attica earthquake, searched for earthquake-induced liquefaction features in sand and gravel pits and along tens of kilometers of river cutbanks, evaluated numerous soft-sediment deformation structures, compiled geotechnical data and performed liquefaction potential analysis of saturated sandy sediments. We found that the 1929 M 4.9 Attica earthquake probably did not induce liquefaction in its epicentral area and may have been generated by the western branch of the Clarendon–Linden fault system. Most soft-sediment deformation structures found during reconnaissance did not resemble earthquake-induced liquefaction features, and even the few that did could be attributed to non-seismic processes. Our analysis suggests that the magnitude threshold for liquefaction is between M 5.2 and 6, that a large (M≥6) earthquake would liquefy sediments at many sites in the area, and that a moderate earthquake (M 5–5.9) would liquefy sediments at some sites but perhaps not at enough sites to have been found during reconnaissance. We conclude that the Clarendon–Linden fault system could have produced small and moderate earthquakes, but probably not large events, during the Late Wisconsin and Holocene.