Estimation of the determination error of the solid-phase density of disperse soils by different methods

The accuracy and reliability of the determination of the solid-phase density (SPD) for disperse soils by the standard method (State Standard 5180-84) and by the Kalachev rapid method were estimated. The causes for discrepancies in the SPD determination in clay soils between the two different methods were determined for the cases of similar and different preanalysis preparations. A justified calculation procedure for the determination of the bound-water density in clay soils, which is adequate for the nature of complex physical phenomenon, was developed. Corrections for the bound-water density in clay polymineral soils with different dispersion properties are suggested.     

Report of the International Association of Geoanalysts on the Certification of Penrhyn Slate, OU-6

The International Association of Geoanalysts (IAG) has certified a slate sample, OU-6, for twelve major and minor constituents, as well as thirty-five trace elements through an interlaboratory programme conducted in close compliance with the International Organization for Standardization (ISO) Guide 35 (1989). Laboratories were qualified for participation in the certification programme, based on their performance in the prior analysis of OU-6 as a proficiency test material. Thirty laboratories provided data for the certification, though not for each constituent that was certified. Certification criteria included a means of establishing traceability for the certification data, generally through concurrent analysis of the existing Geological Survey of Japan reference material JSl-1, agreement of results between laboratories and methods, and a minimum of data rejection (4% rejection rate for OU-6 data and 6% for JSl-1 data), preferably for well-understood technical reasons only. Information values are provided for an additional eight constituents where certification criteria were not met. Uncertainties developed in accordance with the "Guide on Uncertainty in Measurement" (Eurachem 2000) and representing the 95% confidence interval of the certified and information values are reported for all fifty five constituents. The material is currently available in 40 g units for distribution by the IAG. Supply is anticipated to last about ten years.     

尾矿坝渗透静力稳定分析

边坡稳定的条分法中,条间剪切力的作用效应根据分析方法的不同,对稳定系数的计算结果存在较大的差异。有效应力分析方法中依据渗流场的计算分析得到条间孔隙水压力。基于Bishop条间力的假定原理,提出一种新的条间孔隙水压力的分析方法,以确定边坡的最小稳定系数。实际工程计算反映出不同计算方法的差异及新方法的实用性。     

考虑参数和模型不确定性的基桩正常使用极限状态可靠度分析

考虑承载力计算模型和荷载不确定性,利用可靠度分析方法和概率统计理论,推导出承载能力极限状态（ULS）和正常使用极限状态（SLS）下可靠度指标的计算公式,给出了两种极限状态下可靠度指标间的线性关系式,研究了桩顶容许沉降 随机性对正常使用极限状态可靠度分析结果的影响。研究结果表明,土体类别和桩型对正常使用极限状态模型因子影响很小;正常使用极限状态下基桩可靠度指标随承载力计算模型和荷载不确定性的增大而减小,但减小幅度逐渐降低,且可靠度指标总变化量不大,工程应用中可忽略承载力计算模型和荷载不确定性在可靠度分析中的影响; 随机性对正常使用极限状态可靠性分析结果的影响很大,随 的增加,正常使用极限状态模型因子和可靠度指标逐渐增大,而模型因子变异性逐渐减小,但桩本身性质并没有任何改变,只是所允许的沉降条件不同。研究结果可为规范修订和工程应用提供参考。     

群锚静载试桩研究

应用全长粘结式锚杆群代替反力桩进行桩基静载试验,不但工艺简单、施工方便,而且工期短、成本低。通过对锚杆的力学分析和现场量测,获得了锚杆的受力和位移特征,为这类锚杆的设计与计算提供理论依据。     

Asymmetry function of interstellar scintillations of pulsars

A new method for separating intensity variations of a source’s radio emission having various physical natures is proposed. The method is based on the joint analysis of the structure function of intensity variations and the asymmetry function, which is a generalization of the asymmetry coefficient and which characterizes the asymmetry of the distribution function of intensity fluctuations on various scales for inhomogeneitiesin the diffractive scintillation pattern. Relationships for the asymmetry function in the cases of a logarithmic normal distribution of the intensity fluctuations and a normal distribution of the field fluctuations are derived. Theoretical relationships and observational data on interstellar scintillations of pulsars (refractive, diffractive, and weak scintillations) are compared. The data for PSR B0329+54, B1133+16, B1642-03, and B1933+16 pulsars were used for comparison. Pulsar scintillations match the behavior expected for a normal distribution of field fluctuations (diffractive scintillation) or logarithmic normal distribution of intensity fluctuations (refractive and weak scintillation). Analysis of the asymmetry function is a good test for distinguishing scintillations against the background of variations that have different origins.     

站队结合流量测次精简分析方法的研究

为适应站队结合的需要，必须对流量测次作精简分析。本文以湖南省株洲站队结构区为研究实例，在测站特性分析的基础上，根据水力因素和环境因素对水位流量关系的影响，将区内测站按水位关系稳定，较稳定、不稳定进行分类。     

Estimate of the accuracy of the linear-caustic approximation in analyses of gravitational microlensing observations

The amplification coefficient for gravitational lensing of a point source in the linear-caustic approximation is compared with exact values calculated for a lens comprised of two point masses. Even in the most favorable case for the caustic crossing, the error in the amplification coefficient remains below 1% only for distances to the caustic not exceeding 0.01 of the Einstein radius.     

Integrated assessment and evaluation of the coastal environment of the province of vizcaya,bay of Biscay,Spain

A methodology for the quick, overall assessment of the capability of different parts of a coastal environment to be used for human activities is described. The methodology is based on the elaboration of a series of thematic maps (geologic, biologic, and dynamic, e.g., currents, features) for the three “environmental systems” that were defined (marine, estuarine, and emerged coastline). The thematic maps are combined to define “homogeneous units” and these are then evaluated for the attractiveness and impact corresponding to a series of selected activities. Alternatively, the mapped features can be evaluated directly for certain systems, without defining homogeneous units. The combination of attractiveness and impact is used to obtain the relative capability of each unit for each activity, thus establishing the activities that are most advisable in each case.     

关于现行《岩土工程勘察规范》部分条文的讨论

现行《岩土工程勘察规范》是岩土工程勘察行业最具有强制性、权威性、约束性的国家技术标准。根据大量的工作实践和交流、对比、分析,对《岩土工程勘察规范》的适用范围、岩石质量指标、地震效应、水土腐蚀性判别等部分条款的规定和实践中操作的可行性作一交流,供同行讨论,也供国标再修订、编写时参考。     

软黏土蠕变模型参数的确定方法研究

土的蠕变问题进行数值分析一般都需要用黏弹塑性有限元的方法来求解,如何取参数是关键性的问题。软黏土的蠕变过程可能持续几十年甚至上百年的时间,而实验室中的实验一般只进行几个小时或者几天最多几个月的时间,因次,用短时间的实验数据来外推长时间范围的结果就显得非常重要。提出了利用实验数据估算软黏土蠕变模型有限元参数的方法,并利用黏弹塑性有限元程序计算天津港突堤蠕变问题的计算结果来分析模型参数的变动对蠕变问题的计算结果的影响。采用了所提出的参数分析和评价方法的黏弹塑性有限元系统被运用于多项工程计算中,取得了良好的效果。     

贵州织金县城岩溶地下水脆弱性评价

本文在全面分析织金县城地下水岩溶流域的水文地质、岩溶地质特征的基础上,参照有关评价的理论数据提出了适合该区域的地下水脆弱性评价系统与DRKST模型,并结合GIS空间分析功能对岩溶流域地下水脆弱性进行了评价,对规划织金县城的建设和发展,具有较大的参考价值。     

水稻籽实及其根系土壤中镉含量的相关性研究——以几个金土地工程土地整理区为例

通过对水稻籽实（大米）及其根系土壤中镉含量的相关性研究表明：酸性水稻土壤区域,根系土中的镉与水稻籽实中的镉相关系数为0．971,说明大米中镉积累与土壤环境中镉含量密切相关。碱性水稻土壤区域,水稻根系土中的镉与水稻籽实中的镉相关系数为0．265,大米中镉含量较低,碱性土壤中镉不易活化而原地淀积,则根系土壤中镉对大米中镉的富集贡献小。水稻根系土壤中有机质（Org）与镉相关系数为0．59,也较为显著。土壤中有机质对重金属元素镉具正吸附作用,有机质含量越高,重金属元素镉呈难吝硫化物而原地淀积。     

钻井液流变参数计算方法的分析及流变模式的优选

钻井液流变模式的合理选择和流变参数的准确计算是钻井液优化设计的前提。针对目前比较常用的5种钻井液流变模式，分析了流变参数的常规计算方法并指出了其不足；利用回归分析的数学方法，对5种流变模式下流变参数进行了数据处理；开发了计算机软件，对流变参数的2种计算方法进行了比较和分析，充分体现线性回归的先进性和准确性。通过计算机软件计算流变参数，输出各流变模式的流变曲线，从而实现流变模式优选。     

福建省大田县土地利用适宜性评价

新修订的《中华人民共和国土地管理法》已于１９９９年元旦实施,其重要特点之一是实行土地用途管理,限制农用地转为非农建设用地,确保耕地动态平衡,因此,必面编制土地利用总体规划,而土地适宜性评价是“规划”编制的基础,也是各级政府土地利用决策的依据之一。我们在编制大田县土地利用总体规划中,对该县建设用地,水域,裸岩地以外的大部分土地作了适宜性评价,划分了宜耕,宜园,宜林地和暂不适宜土地,并进一步划定了适宜     

Potential of High-Resolution Satellite Data in the Context of Vulnerability of Buildings

High-resolution space-borne remote sensing data are investigated for their potential to extract relevant parameters for a vulnerability analysis of buildings in European countries. For an evaluation of large earthquake scenarios, the number of parameters in models for vulnerability is reduced to a minimum of relevant information such as the type of building (age, material, number of storeys) and the geological and spatial context. Building-related parameters can be derived from remote sensing data either directly (e.g. height) or indirectly based on the recognition of the urban structure type in which the buildings are located. With the potential of a fully- or semi-automatic inventory of the buildings and their parameters, high-resolution satellite data and techniques for their processing are a useful supporting tool for the assessment of vulnerability.     

CO2矿物捕获能力的研究进展

全球碳存储的研究表明, CO2最稳定的存储方式是 CO2的矿物捕获, 即将 CO2注入到地下,使其以方解石、菱铁矿、白云石及片钠铝石等碳酸盐矿物的形式存在.适合 CO2矿物捕获的岩石类型主要有火山岩、砂岩和火山碎屑岩.分析了3种岩石类型的金属元素含量、金属元素的释放能力、与 CO2反应生成的矿物类型及对 CO2的捕获量,并比较了3种岩石类型对 CO2矿物捕获能力的差异.其中玄武岩等火山岩的金属离子含量高,但其孔隙空间有限,制约了成岩反应,且 CO2注入后具有逸散的风险;砂岩分布广泛,有足够的孔隙利于流体注入,但是金属离子含量相对较低,对 CO2的矿物捕获所需时间相对较长;火山碎屑岩则结合了前2种岩石类型在矿物捕获方面的优势,是一种理想的 CO2矿物捕获的岩石类型.     

膨胀土损伤变量不同表征方法评价的试验研究

裂隙性是膨胀土的重要结构特征,裂隙损伤对膨胀土的变形、强度和稳定性有重要影响。岩土体损伤演化理论是当前研究的前沿课题,选择合理的损伤变量决定着损伤模型的正确性。为评价几种损伤变量表征方法的合理性,以南水北调中线工程陶岔引水渠坡的膨胀土为试验研究对象,通过控制净围压和吸力分别为100、50 kPa下的CT-三轴剪切试验,定量研究了分别基于承载面积、CT数的均值ME和方差SD的损伤变量表征方法的合理性。研究发现,损伤面积相同而损伤部位不同的试样偏应力-应变曲线和强度基本一致;损伤面积和SD可以作为损伤变量表征参数,而ME不适合用来表征膨胀土的损伤变量,虽然ME可以很好地用来定义岩石的损伤变量。试验研究结果可以为建立考虑损伤的膨胀土强度理论和本构模型中损伤变量的选择、定义提供科学依据。     

Excitation of Under-Ice Seiches of a Sea Port of the Sea of Okhotsk

Doklady Earth Sciences - Multiannual observations (2009–2017) by means of autonomous seiche recorders have been conducted for marine seiches with one second discreteness in the boot basin for...     

离心模型挡土墙试验设备的研制

土压力问题是土力学和岩土工程领域的基本研究课题。土压力离心模型试验是验证土压力计算方法和研究土压力形成物理机制的有力工具。笔者研制开发的土压力离心模型试验设备,可用于刚性挡墙的静止土压力和平动模式下主动侧土压力的研究。该设备采用电机作为驱动系统,使得挡墙能够缓慢均匀地位移;配备有控制挡墙位移的自动控制系统,使得挡墙在离心加速度增大的过程能够保持静止状态。针对填土面水平、墙后填土为砂土的情况进行了离心模型试验,测量了墙背土压力及填土位移场随挡墙位移量的变化。试验结果规律好,验证了设备的有效性。