利用"岩体裂隙率"评价工程岩体的质量

本文提出用建立在岩体结构面网络三维模拟基础上的“岩体裂隙率”来表征岩体的质量。它可以用来衡量结构面的发育程度及岩体的完整性，评价岩体质量，用于工程岩体分类。     

红石岩震损高陡边坡工程岩体质量评价

高陡岩质边坡在经历强震过后,其浅部岩体受地震动力瞬时循环载荷作用而导致岩体质量下降,即所谓震损边坡。震损边坡的工程岩体质量对施工措施的制定和边坡安全评价至关重要。针对震损边坡岩体的实际特点,以工程岩体质量评价的BQ分级体系为基础,应用三维激光扫描技术来识别岩体结构面和节理裂隙,并结合岩块单轴抗压强度试验,建立了震损边坡工程岩体质量评价方法。应用提出的方法对云南鲁甸红石岩震损边坡Ⅱ区进行工程岩体质量评价,分析结果表明:震损边坡Ⅱ区浅部岩体较为破碎、受长期卸荷和地震扰动影响,节理裂隙发育,运用三维激光扫描技术识别、统计岩体结构面情况,再结合常规的岩体质量分类方法,最终确定岩体分级为Ⅳ类,结果较符合实际情况。该方法能够远程非接触式地识别统计岩体的结构面信息,尤其适合岩体破碎或坡面高陡而技术人员无法到达的危险边坡的岩体质量评价,可为其他类似工程提供参考。     

运用结构面模拟技术分析岩体质量特征

在总结以往岩体质量分类经验基础上，突出岩体的结构特征分析与研究，阐明了岩体质量评价的理论、方法、指标体系，结合实例建立了一种简洁、实用的岩体质量评价体系。在这一系统中，突出了岩体结构面网络模拟分析在评价中对确定RQD值的重要作用，解决了RQD值的定量分析，对岩体质量评价向定量化发展具有重要意义。通过工程实践说明这一评价体系对工程建设具有重要指导作用。     

试用灰色关联分析评价工程岩体质量

笔试用灰色关联分析评价工程岩体质量，取得了较好的效果，该法可在工程岩体评价中推广应用。     

三维岩体质量的多重分形评价及分类

岩体中结构面的存在往往会对岩体质量造成显著影响。笔者剖析了传统岩体质量指标的不足,以白云鄂博铁矿主矿边坡岩体为例,在工程地质测绘的基础上,利用蒙特卡洛（Monte Carlo）法仿真出三维岩体结构网络图,从多重分形几何的角度出发,计算和绘制出其表征岩体结构分布和复杂性的多重分形谱,对岩体质量作出定性评价和定量分析,并且进行了岩体质量的多重分形分类。     

基于三维地层模型的岩体质量可视化分级

岩体质量分级是岩石力学学科研究的热点和难点,在水电工程建设中具有重要的实际意义。在对岩级分类方法进行大量研究之后,工程人员对岩级结果的表达有了更高的要求,传统的方式已不能满足人们空间分析的需要,研究岩体质量可视化分级十分必要。首先,利用NURBS工具以一种新的数据结构和方法重建三维地层模型,然后,基于岩体质量分级结果,按照空间图形集合运算算法生成相应的三维岩级模型。将上述理论方法应用到锦屏一级水电工程岩体质量分级评价中,并进行了一系列与工程相关的岩级可视化分析,获得了很好的应用效果。     

基于GIS技术的岩体裂隙分形特征研究

基于GIS技术,对我国高放废物地质处置库预选区岩体裂隙测量数据进行可视化处理,计算反映岩体裂隙发育情况的分形特征参数,并应用于工程岩体质量评价。为岩体裂隙的定量化与模型化研究提供了新思路。     

结构面三维网络模拟在岩体质量评价中的应用

岩石质量指标RQD是反映工程岩体完整程度的定量参数,广泛用于水利水电、矿山、地下工程、交通工程等岩体稳定性评价,但是传统的RQD定义不能满足实际工程岩体各相异性要求。针对贵州黔中水利枢纽工程拱坝坝基岩体结构面特征,利用Monte-Carlo法在计算机上生成岩体节理三维网络图,建立了模拟计算不同阀值t的岩石质量指标RQDt的计算机模拟方法。该方法能较真实客观地描述岩石质量。     

考虑岩体开挖卸荷边坡岩体质量评价

正确评价开挖后岩体质量并对其进行分类,对研究岩石边坡开挖卸荷后的稳定性有十分重要的意义。以某水电站坝肩高边坡开挖工程为背景,运用卸荷岩体力学的理论与方法,对坝肩边坡开挖岩体进行三维有限元分析。根据边坡岩体开挖后应力应变场的动态变化情况,确定岩体开挖卸荷后质量损伤劣化程度,并根据岩体开挖卸荷后的力学参数,采用RMR法对开挖后的边坡岩体质量进行评价。结果表明,边坡岩体RMR值随开挖后卸荷量的增大基本呈线性递减趋势,进而考虑开挖卸荷影响因素,修正了RMR法中的评价参数,为以后用该法评价开挖后的岩体质量提供参考。     

基于改进Dempster-Shafer证据理论的岩体质量异质集成评价方法

为客观获取准确可靠的岩体质量评价结果,针对现有单个评价模型容易产生误判与偏倚现象,提出基于改进D-S(Dempster-Shafer)证据理论的岩体质量异质集成评价方法。在确定岩体质量评价标准与数据集的基础上,采用6个异质基分类器对数据集进行训练,获得初步岩体质量评价结果。将每个基分类器结果作为一条证据,经过改进D-S证据理论对各证据进行集成,形成综合评价结果,解决现有评价方法的结果非一致性问题。以30组样本构建基于改进D-S证据理论的异质集成评价模型,并运用于广州抽水蓄能电站二期工程岩体质量评价中。结果表明：基于改进D-S证据理论的异质集成评价方法提高了岩体质量等级的识别准确性和可靠性,能够避免评价过程中的主观性与不确定性,具有较高的工程实用价值。     

Computer application on evaluating beach sediment erosion and accretion from profile survey data

Handling and visualizing of beach profile data using visual programming provides better and more user-friendly effects to geologists, environmentalists, and policy makers. Several computer programs are available to visualize beach profile data. But in all programs, the raw field data cannot be used to calculate the sediment erosion and accretion. In this report, we describe the development of a simple piece of software BEACH using Visual Basic 6.0 that can store and analyze large volumes of profile survey data obtained from graduated pole or level surveys. The program precisely calculates the beach width, slope, and sediment volume above any user-specified datum. It also estimates the erosion and accretion made in a beach. This program is very useful for coastal zone management and environmental impact assessment studies.     

Petrography and depositional environment of the liddell seam, upper hunter valley, New South Wales

The Liddell Seam occurs in the lower part of the Permian Foybrook Formation of the Sydney Basin, eastern Australia. The seam profile is dominated by banded lithotypes (clarain). Maceral and microlithotype analyses of lithotypes indicate a limited degree of uniformity in their composition. A comparison of whole-seam petrographic analyses with compositions calculated on the basis of the seam lithotype profile and lithotype petrography suggests that the latter method may provide for a rapid assessment of petrographic variation in operating mines.Petrographic analyses form the basis of an interpretation of Liddell peat-swamp facies. The seam contains few clastic layers which are associated with relatively dull coals whose petrography reflects elevated water levels during deposition in the limno-telmatic, reed-moor and open-moor facies. Between these zones the seam profile is dominated by relatively bright coals deposited between periods of inundation, in the telmatic forest-moor and reed-moor zones. The lithotype profile and the high vitrite and clarite content indicate the significant influence of arborescent vegetation, a feature typical of seams deposited in tectonically unstable areas.     

Techniques for slope stability analysis: Site specific studies from Idukki district,Kerala

The occurrences of slope failures are frequent in Idukki district of Kerala state particularly along the road cuttings and hill slopes causing disruption in traffic, loss of lives and property. This demands a critical evaluation of stability of slopes along the hill roads. This paper deals with stability analysis of a typical hard rock profile at Chuzhappu and a lateritic profile at Kumili along the road connecting Kottayam and Kumili. A large number of factors have been examined and studied; the orientation of discontinuities has been identified as one of the major inherent factors influencing slope instability along Chuzhappu hard rock profile. These have been analysed carefully using stereographic/equal area projection technique in order to determine the vulnerability to slope failure and to understand the type of rock slide that can occur in this profile. The buoyant force of water acting along the discontinuities after heavy rain storm further aids the down slope movement. As the laterite slope is mostly homogeneous, Bishops method and Swedish method were adopted for stability analysis of laterite slope at Kumili. The study also examines the efficacy and applicability of the different methods employed in soil mechanics to assess the stability of laterite slope.The results obtained by this method are compared by actual field conditions. The stability assessment indicates that two sectors at Chuzhappu and one sector at Kumili profile are at the geo-technical threshold of failure, when piezometric head rises during rainstorm. The study indicates that these methods are highly useful in determining the Factor of Safety in profiles with similar geological setting.     

基于改进突变理论的滑坡危险性评价

滑坡危险性评价是滑坡风险评估的重要组成部分,对滑坡的预测和防治意义重大。传统滑坡危险性评价在计算指标间重要性时多采用AHP、专家评判法、模糊综合评判等方法,但存在主观性较强,计算较为复杂等问题。研究基于一种改进的突变理论模型对滑坡进行危险性评价,选取坡度、坡向、高程、平面曲率、剖面曲率、距河流距离、地层岩性、土地利用类型、距断层距离、植被覆盖率、24 h降雨以及人类工程活动等12个因子作为滑坡危险性评价的影响因子,采用熵权法判定指标间的相对重要性,并建立滑坡危险性评价体系;然后对指标进行标准化、归一化,计算总突变结果;最后使用拟合函数对总突变结果进行转换,得到新的滑坡危险性评价准则,并以雅安市的20条滑坡对评价准则进行实例验证。结果表明,突变理论得到的评价结果准确率为90%,评价结果更加直观准确。     

Flood and earthquake disturbance of 210Pb geochronology (Lake Anterne, NW Alps)

Dating recent lake sediment records yielding disturbed ²¹⁰Pb profiles has been a problem of wide interest in palaeoclimatic and palaeoseismic studies over the last few centuries. When applied to an alpine lake sedimentary record, a high-resolution sedimentological study reveals that the ²¹⁰Pb profile is disturbed by the occurrence of single-event deposits triggered by two different mechanisms: flood events deposits and gravity reworking. Removing disturbed layers from the ²¹⁰Pb profile yields a logarithmic depth–activity relationship. Using a simple ²¹⁰Pb decay model (CFCS) provides an assessment of mean accumulation rate of `continuous sedimentation', as opposed to `event-linked sedimentation'. The correlation of the thickest four gravity-reworked deposits with historically known earthquakes permits both validation and refinement of the age–depth relationship. This refinement highlights variations in accumulation rate consistent with post-Little Ice Age climatic variations.     

基于随机森林回归分析的岩体结构面粗糙度研究

岩体结构面粗糙度系数是快速估算结构面峰值抗剪强度的重要参数。但是结构面轮廓曲线复杂,单一统计参数无法量化表征粗糙度。为解决这一问题,收集了112条结构面轮廓曲线起伏角、起伏度、迹线长度3方面的8项统计参数,利用随机森林回归模型交叉验证的方法评估统计参数的重要性。结果表明：最大起伏度、起伏高度标准偏差、平均起伏角、起伏角标准差、平均相对起伏度及粗糙度剖面指数等6项统计参数重要性占比达到93.2%,且回归拟合系数趋于平稳,基于重要性评估结果建立最优超参数决策树数目(n_tree)为400、参与节点分割的数目(m_try)为2的随机森林回归模型,模型预测结果拟合优度高达98.1%。与基于坡度均方根、结构函数及粗糙度剖面指数等传统线性回归结果对比,随机森林回归模型结果精度更高,误差更小,拟合优度提高6%以上,表明随机森林回归模型更适用于结构面粗糙度反演。     

An atmospheric instability derived with MODIS profile using real-time direct broadcast data over the Indian region

In this study, assessing the atmospheric instability, a new index, named here as MODIS (Moderate Resolution Imaging Spectroradiometer) profile index (MPI), has been statistically computed using temperature and moisture profile data from the real-time direct broadcast receiving systems installed at three places of India Meteorological Department. The training dataset has been prepared using MODIS temperature and moisture profile from the Aqua and Terra satellites over the Indian region for clear and convective weather conditions during the period of March to June 2011. The MPI values are produced at 5?×?5?km pixel resolution when at least 6 out of 9 FOVs from MODIS granules are found cloud free. If more than 3 FOVs are cloudy, the MPI has not been computed. The formulation of MPI and its comparison have been examined with well-established traditionally used K index, Lifted Index and total totals index derived from radiosonde profiles of temperature, pressure and humidity. It has been observed that in most of the cases, MPI has well correlated with those derived from ground truth observations. Therefore, spatially interpolated MPI can be utilized as an indicator for regional and location-specific forecast over the areas where radiosonde data are not available. The results also indicated that MPI can be used as a sensitive measure in very early stages of instability developments such as thunderstorm and rainfall because no other single stability index can provide a distinct threshold value for these events. Therefore, a single MPI value at a certain threshold can be treated as a stability index instead of other available indices. It is also being proposed that the inclusion of MPI as a stability parameter in physical or numerical modeling can improve accurate local severe storm predictions as a useful predictor and can also be used as diagnostic tools. The MPI can make a useful simulation using entire temperature and moisture profile data for the assessment of instability significantly to severe weather forecasting since other instability indices are often derived from a fixed pressure level quantity of vertical profile parameters.     

常规直流电法在黄河水库南屯地质灾害评价中的应用

黄河水库南屯进行勘查的主要目的就是通过物探方法初步查明地下溶洞存在的情况以及区内的地质概况,为该区地质灾害的评价提供必要的参考依据。通过多种物探方法实验,发现激电中梯、激电联剖及视电阻率测深效果相对较好。由于区内地下水较发育,而且已知塌陷部位都不同程度的含水,水导电性能好.。因此,在地表观测时呈现视电阻率低阻趋势。当溶洞中没有地下水存在时,视电阻率呈现高阻异常。这样就可以通过视电阻率的反映来发现地下溶洞。     

滑坡运动路径复杂度研究:综述与展望

滑坡运动路径具有普遍的复杂性,体现为侧散、转向、分叉、交织、聚合与并联等复杂行为.滑坡运动路径复杂性增大了滑坡危险性.因而,滑坡危险性评估对滑坡运动路径复杂度的量化和概率分布研究提出了需求.系统地梳理和总结了滑坡运动路径复杂度的研究现状,指出了相关研究所面临的关键问题,并进行了未来研究展望.总体上,当前关于滑坡运动路径复杂行为的研究,主要面临量化研究稀缺、概率分布研究欠缺的问题.具体表现在:现有滑坡运动路径的剖面线概化方法难以处理多路径复杂行为;现有零星的指标不能满足滑坡运动路径复杂度的系统性科学量化;滑坡运动路径复杂度概率分布的分布函数不明、主控因素不清.进一步,针对待解决的关键问题,本文在研究展望中提出:主要通过分段单路径化方案,实现滑坡运动多路径复杂行为的剖面线概化;构建基于剖面线的滑坡运动路径复杂度的量化指标体系,突破量化难题;基于大量滑坡实例数据,确定滑坡运动路径复杂度概率分布的分布函数、查清其主控因素;最终,实现滑坡运动路径复杂度概率分布的预测建模,支撑滑坡危险性及风险定量评估.      

容许土壤流失量的研究现状及其设想

成土速率、土地生产力和沟蚀的控制程度是容许土壤流失量（[WTBX]T值）制定中必不可少的因素。国际上现有的T值标准主要是从土层厚度和成土速率出发,并结合实际应用的可能而定。详述了T[WTBZ]值的研究历史其主要影响因素,介绍了利用Barth模型和基于风险评价理论的[WTBX]T值的估算方法,对现有T值研究方法和研究结果中存在的问题进行了分析,提出了T[WTBZ]值应该从土壤形成速率特性（自然属性）、合理的生产力水平持续性（社会属性）、水土环境的长久安全性（自然和社会属性）几方面属性进行相应的研究。