浅谈钻孔抽水试验的设计与实施

钻孔抽水试验时,试抽出的钻孔涌水量远远超出预测且降深也无法满足规程要求时,只有根据试抽水的结果,重新设计抽水试验方案,重新选择井管的内径、抽水设备以及参数,风、测管的口径和下入深度等.本文通过一个钻孔抽水试验的经过,说明按规程选择以上各参数的方法及意义.     

水泥-水玻璃浆液性能试验研究

本文针对灌浆材料应用广泛的实际 ,选择水泥 -水玻璃浆液进行研究 ,通过对其主要性能参数的试验分析 ,得出了该类浆液的最优配比方案 ,实现了性能优良、经济合理的目的 ,以便满足实际工程的需要。     

中低水流量测验精度试验研究

针对黄河中游水文测区流量测验可能存在误差来源,选择黄河中游重要水沙控制站——吴堡水文站,分别进行了中低水流量测验测深误差试验、测宽误差试验、Ⅰ型误差试验、Ⅱ型误差以及Ⅲ型误差试验,在误差试验研究和测流方案分析的基础上,提出了满足《河流流量测验规范》要求的中低水流量测验方案。     

大面积堆载试验现场地基沉降分析

结合上海浦东国际机场场道工程软土地基处理方案选择研究,通过模拟道面结构荷载条件下地基的地表沉降和分层沉降的长期观测资料,对大面积堆载试验现场地基土的最终沉降、工后残余沉降以及沉降的组成情况进行了深入的分析和探讨。     

地基处理方案的模糊判别选择

采用何种地基处理方法,直接影响到地基处理的效果和造价,长期以来选择地基处理方案都是根据经验确定.文章采用层次分析法试图建立起地基处理方案选择评价体系,通过对比,在实际应用中达到优化选择地基处理方案的目的.     

管井施工质量控制

通过施工前资料收集、定位、施工单位和设备的选择等的准备,施工前设备的精心调试安装、钻进、测井、制定最佳成井方案、及下管、投砾、抽水试验到验收等过程的质量控制研究,达到保证管井施工质量,提高单井出水量,创造最佳经济效益。     

采用压浆法控制地面沉降和提高挡土墙强度工程实践

通过用压浆法对核力机械股份有限公司厂房内、外的地面沉降、开裂和挡土墙裂缝进行控制性治理之工程实践,阐述了在土层结构复杂、性状不稳定等情况下,在制定方案、参数选择和工程实施过程中,应把施工经验、理论计算、试验资料和工程实际进行综合分析,及时调整设计和施工方案,保证安全,确保工程质量。在分析地面沉降、开裂和挡土墙裂缝产生的原因基础上,提出了治理方案,并详细介绍了治理方案实施过程中的技术措施。     

石膏质岩的膨胀特性及防治对策研究

以宜巴高速路凉水井隧道出露的石膏质岩为研究对象,通过室内试验,分析研究了试样的自由膨胀率和无荷载膨胀率试验。在室内试验的基础上,结合石膏质岩的膨胀特性,给出了隧道工程防治石膏质岩膨胀变形的防治措施。研究表明:试样的自由膨胀率可达4.1%,无荷载膨胀率最大为5.86%;膨胀变形过程会放出较多热量,且膨胀变形周期较长;在隧道穿越石膏质岩勘查设计阶段,必须进行详细的勘查,提供准确的勘查数据;在隧道穿越石膏质岩施工支护阶段,需要选择合理的开挖方案和支护方案     

基于模糊决策的立井堵水注浆方案选择及其应用

影响注浆工程质量的因素存在一定模糊性,如何选择正确的注浆方案,对提高工程质量有重要作用.基于此,本文采用模糊数学的方法对影响竖井堵水注浆工程的诸多因素建立模型,并通过分析和研究对竖井堵水方案进行优选.通过实践表明,运用模糊数字方法选择注浆方案,对注浆工程的设计与施工具有一定指导意义.     

砂岩型铀矿铀源岩中活性铀浸出方法研究

通过对砂岩型铀矿铀源岩样品中活性铀的浸出试验，选择了相对合理的浸取剂，讨论了样品粒度、固液比、称样量、温度、时间等因素对铀浸出率的影响，拟定了一个适用性广，操作条件较宽松、质量稳定的浸取体系和分析方案。该分析方案对不同类型铀源岩中活性铀的浸出率测量相对标准差小10％（n=11）。     

短程红外测距仪周期误差检测中几个问题探讨

本文应用数理统计方法和误差理论,讨论了短程红外测距仪周期误差检测中的观测点数,并推导出数理统计显著性检验实用公式。同时,对呆用平台法检测周期误差的棱镜对点精度进行了分析。     

Validation and Evaluation of Predictive Models in Hazard Assessment and Risk Management

The paper deals with the validation and evaluation of mathematical models in natural hazard analysis, with a special focus on establishing their predictive power. Although most of the tools and statistics available are common to general classification models, some peculiarities arise in the case of hazard assessment. This is due to the fact that the target for validation, the propensity to develop a dangerous characteristic, is not really known and must be estimated from a (usually) very small sample. This implies that the two types of errors (false positives and false negatives) should be given different meanings. Related to this, a very frequent situation is the presence of prevalence (different proportion of positive and negative cases) in the sample. It is shown that sample prevalence can have a dramatic effect in some very common validation statistics, like the confusion matrix and model efficiency. Here some statistics based on the confusion matrix are presented and discussed, and the use of threshold-independent approaches (especially the ROC plot) is shown. The ROC plot is also proposed as a convenient tool for decision-taking in a risk management context. A general scheme for hazard predictive modeling is finally proposed.     

长春地区老黏土地基承载力确定方法的探讨

老黏性土工程实践经验较多,根据其他省市地区的成熟经验,用数理统计法确定老黏性土地基承载力可根据土的室内土工试验物理力学性质指标孔隙比、液性指数查表求得,还可根据原位测试静力触探指标和标准贯入试验指标确定.本次试验利用这些成熟经验,通过分析土工试验、原位测试指标与静载试验测得的地基承载力的对应关系,总结出用土工试验物理力学性质指标、原位测试静探指标计算老黏性土地基承载力的经验公式和经验表.     

水文地质数据数理统计程序设计与实现

应用数理统计方法可提取大量随机水文地质数据的重要特征。本文设计的程序实现了对大量随机数据的统计计算、确定元素含量背景值及概率分布型式的检验等水文地质工作中常用统计方法。     

静压管桩单桩极限承载力与终压力关系的探讨

通过静压管桩单桩承载力的静载荷试验研究,依据Q-S曲线等试验成果给出单桩极限承载力,采用数理统计方法探讨单桩极限承载力和终压力之间的区别和联系,提出两者之间的相关估算方法,为静压管桩技术的进一步推广和应用提供一定的依据。     

新疆罗布泊地区盐渍土分类定名方法探讨

盐田是卤水提钾生产中最基本的组成部分,在选址中,需要确定选区是否存在连续的粘性土层作为盐田隔水底板。但由于选区面积大,试样数量巨大,实验周期长,经费投入大,无法满足要求。运用数理统计原理,在全区范围内均匀选取具有代表性样品用洗盐后的塑性指数IP'与洗盐前的塑性指数IP进行数理统计分析,得出回归方程IP'=2.27400+0.98118×IP,用此方程可得出洗盐后盐渍土的塑性指数,用于全区的岩土分类定名,不但满足了要求,也产生较大经济效益。     

岩土混合边坡预应力锚杆支护数值模拟：以深圳金园路边坡为例

预应力锚杆支护是一种较新型的锚固技术,但实际工程设计都偏保守,造成经济浪费,因此实际设计过程中存在诸多预应力锚杆参数优化问题。使用有限元分析软件Abaqus模拟锚杆长度、锚固角度、预应力、直径诸因素的变化对边坡稳定性的影响趋势,通过正交试验优化设计得出最优组合方案,为预应力锚杆的相关设计提供科学参考,避免工程建设的安全隐患或不合理投资。     

A technique to test finite difference schemes to model some geophysical processes in a geological structure

A preliminary problem to solve in the set-up of a mathematical model simulating a geophysical process is the choice of a suitable discrete scheme to approximate the governing differential equations. This paper presents a simple technique to test finite difference schemes used in the modeling of geophysical processes occurring in a geological structure. This technique consists in generating analytical solutions similar to the ones characterizing a geophysical process, given general information on some relevant parameters. Useful information for the choice of the discrete scheme to employ in the mathematical model simulating the original geophysical process can be obtained from the comparison between the analytical solution and the approximated numerical solutions generated by means of different discrete schemes. Two classes of numerical examples approximating the differential equation that governs the steady state earth's heat flow have been treated using three different finite differences schemes. The first class of examples deals with media whose phenomenological parameters vary as continuous space functions; the second class, instead, deals with media whose phenomenological parameters vary as discontinuous space functions. The finite difference schemes that have been utilized are: Centered Finite Difference Scheme (CDS), Arithmetic Mean Scheme (AMS), and Harmonic Mean Scheme (HMS).The numerical simulations showed that: the CDS may yield physically inconsistent solutions if the lattice internodal distance is too large, but in case of phenomenological parameters varying as a continuous function, this pitfall can be avoided increasing the lattice node refinement. In case of phenomenological parameters varying as a discontinuous function, instead, the CDS may yield physically inconsistent solutions for any lattice-node refinement. The HMS produced good results for both classes of examples showing to be a scheme suitable to model situations like these.     

酸性矿渣粉活性激发剂配方试验研究

采用工业废弃物——酸性矿渣粉取代水泥作为胶凝材料,以激发酸性矿渣粉活性、提高砂浆综合性能、降低矿山充填成本为目的而进行试验研究,以抗压强度为指标,通过单一激发剂、复合激发剂激发酸性矿渣粉制成胶凝材料的试验,确定了激发酸性矿渣粉活性较好的激发剂,然后选取了4种激发剂进行正交试验,得出了3个不同龄期的最优激发配方。解决了酸性矿渣粉难被激发利用的问题。     

Contributory Factors and Distribution Characteristics of Asymmetric Deformation in Deep Tunnel

Aiming at the asymmetric deformation of the surrounding rock in deep tunnels, from the perspective of the mechanical environment of the rock layer, the physical characteristics of the surrounding rock and the geometric characteristics of the tunnel, five kinds of influencing factors for the asymmetric deformation of the tunnel surrounding rock were selected, and the change levels of various factors were established. Through orthogonal test methods, 25 sets of orthogonal test simulation schemes were designed to study the asymmetric deformation law of the surrounding rock of deep roadway under the combined action of various factors. Three surface displacements of the surrounding rock are used as indicators to weigh the influence of various factors on the asymmetric deformation of the surrounding rock. Through the Extreme Difference analysis and F Statistics comparison of the indicators, the dominant influencing factors affect the deformation of the surrounding rock are obtained. By studying the distribution of the maximum deformation position of the surrounding rock, we have obtained the asymmetry characteristics of the surrounding rock deformation. In addition, the simplified mechanical analysis of the key influencing factors of the deformation of the surrounding rock is given, and the distribution law of the asymmetric characteristics of the surrounding rock deformation is summarized. The above research can provide a certain theoretical reference for the asymmetric deformation control and supporting scheme design of the surrounding rock in deep roadway.