Geotechnical study for optimizing the slope design of a deep open-pit mine,India

The study was undertaken to determine the optimal overall slope angle of a lead–zinc mine, which could extend down to a depth of 170 m. Detailed geotechnical investigations were conducted, including geotechnical mapping of existing benches to establish the geometrical and mechanical properties of the discontinuities, the drilling of eight boreholes and the establishment of the physico-mechanical properties of the intact rock. Based on these data, limit equilibrium and numerical simulation techniques were applied to assess the stability of the slopes and determine an optimal slope angle. It was concluded that the overall foot-wall and hanging-wall slopes should be 42 and 48° respectively.      

Extending the Q system's prediction of support in tunnels employing fuzzy logic and extra parameters

Rock mass classifications predict support measures according to expert rules by rating rock mass and taking into account the span of the opening. A similar procedure is adopted, in this work, and computerized using statistics and fuzzy logic. Fuzzy expert systems are trained with data of previously constructed underground openings. Using subtractive clustering the systems have the intelligence to pick up the relations between input and output and define the rules that represent the system's behavior automatically. These systems are found to predict support to be used more successfully than the Q system. With the introduction of extra input variables, which are important in numerical analysis, such as depth and intact rock strength, an extended fuzzy system is developed. This system is suggested for preliminary use as it is able to predict support even better.     

Fuzzy models for analysis of rock mass displacements due to underground mining in mountainous areas

The displacement and deformations of rock mass due to underground mining has often resulted in major disasters throughout the world, frequently inflicting heavy losses of life and damage to property. And these disasters have motivated the development of rock mass mechanics. The prediction of displacement of rock mass and their surface effects is an important problem of the rock mass mechanics in the excavation activities especially the coal and metal mining in mountainous areas. Based on results of the statistical analysis of a large amount of measured data in mining engineering, the fundamental fuzzy model of displacements and deformations of rock mass is established by using the theory of fuzzy probability measures. The theories of both two- and three-dimensional problems are developed and applied to the analysis of engineering problems in excavation and underground mining in mountainous areas. The agreement of the theoretical results with the field measurements shows that our model is satisfactory and the formulae obtained are valid and thus can be effectively used for predicting the displacements and deformations and the safety evaluation of the buildings on the ground.     

树脂类整体地坪施工中基层处理设备与工艺的选择及应用

树脂类整体地坪施工中,最为常用的被用作基层处理施工的设备,主要有抛丸机、铣刨机及研磨机三大类,分别对应的基层处理工艺为喷砂、铣刨及研磨。基层处理的设备与工艺的选择,需要结合每个项目的具体实际情况,根据基材的类型、项目环境的适用性以及所需施工的整体地坪系统类型,综合决定选择最佳的基层处理设备与工艺。     

模糊综合评判法在高层建筑结构优选中的应用

对高层建筑结构选型决策的现状、特点及影响因素作了概括性论述,具体说明了模糊综合评判法在高层建筑结构选型中的应用,详细介绍了如何运用模糊综合评判法进行结构体系的优选,为建筑设计单位提供了科学的决策依据。     

Using the fuzzy multi-criteria model to select the optimal cool storage system for air conditioning

Four existing cool storage systems for air conditioning, chilled water storage, ice storage, phase change material cool storage and high temperature water cool storage, are evaluated and compared in multi-criteria. Due to the availability and uncertainty of qualitative criteria, this paper presents a fuzzy multi-criteria model to select the optimal cool storage system. In the evaluation process, the optimal weighting method combines the subjectivity of decision-maker and the objectivity of numerical data to obtain the comprehensive weights of criteria and avoids the subjective one-sidedness of weights. The fuzzy multi-criteria model applied to select the best cool storage system in detail demonstrates the evaluation process and its applicability in selecting an optimal system. The evaluation results indicate that ratio of cooling density and ratio of cooling capacity are the most important factors in cool storage systems, and ice cool storage system is the optimal option.     

The destressability index methodology for the assessment of the likelihood of success of a large-scale confined destress blast in an underground mine pillar

This paper reviews the conditions associated with violent rock failure in underground mines, and measures that can alleviate or mitigate the effects of rockbursts. Within this context, this paper focuses on destress blasting as a technique for reducing ground stresses in a selected zone of a mine. In particular this paper addresses the issues associated with large-scale choked destress blasts in mine pillars. In this method large amounts of explosive energy are used, resulting in major damage being caused in the targeted area, as well as in a significant quantity of material being dislodged, this ejection resulting in some convergence of the walls, and, in turn, in a local destressing effect.This paper provides the framework for establishing the critical parameters that control the destress blasting process, and investigates the interactions between these parameters. This is achieved by means of the rock engineering systems (RES) methodology, a matrix-based process that allows one to quantify in a systematic manner the interaction between each pair of parameters known to play a role in an engineering process. This has led to the development of a novel empirical method to quantify the likelihood of success of a large-scale choked destress blast in an underground mine pillar, for a given rock mass condition and stress regime. This method, based upon the newly developed destressability index, has been applied to back-analyse a fully instrumented large-scale confined destress blast at Brunswick Mine, in Canada. This index ascertains whether a given situation is conducive to being destressed by means of a large-scale confined destress blast, and, if so, whether the design of the blast is appropriate to achieve this goal.     

An experimental research on the rock cutting process of the gage cutters for rock tunnel boring machine (TBM)

This paper proposed an experimental method to investigate the rock cutting process of TBM gage cutters based on the full-scale rotary cutting machine (RCM). The key point of this method is to reconstruct the RCM by inserting three wedges with angles of 10°, 20° and 30° respectively into the space between the cutter base and cutter box. As a result, the rock cutting process of gage cutters with tilt angles of 10°, 20° and 30° can be proceed. Using this method, rock cutting experiments were conducted with penetrations of 2 mm, 4 mm, 6 mm and 8 mm respectively. The testing results were analysed on the rock cutting force, rock debris dimension, specific energy and cutting surface profile, and it was found that: (1) the cutting forces and specific energy of the gage cutter were lower than those of the normal cutter respectively; and (2) the depth of the rock broken zone was smaller than the cutting depth. The testing results can also be used to validate corresponding numerical models and design the layout of gage cutters.     

低丘坡地基坑支护方案的选择与应用

据基坑现场实际,经分析比选,确定分段采用坡率法与土钉墙支护的施工方案。监测结果表明,该选型方案合理,具有安全可靠、施工简便、节约造价的优点。     

An application of the thermo-radiative model SOLENE for the evaluation of street canyon energy balance

This paper presents a validation of the thermo-radiative model SOLENE and its application for analysing the street canyon energy balance. The validation data were selected from the temperature and radiation measurements obtained during the JAPEX campaign, previously described by Idczak et al. [16]: a set of four lines of steel containers buildings composing three parallel street canyons at an approximate 1:5 scale. Reference weather data and micrometeorological conditions within the canyon were measured. Numerical simulations were carried out using the meteorological measurements as model inputs. The simulated surface temperatures and radiation fluxes are compared with the measurements for a full week period, with a focus on a day with clear sky conditions. The street canyon energy balance analysis demonstrates that the most energetic surface was the street ground due to its thick surface layer of tar-coated gravels while the walls had a low heat capacity. The thermal radiation balance was negative for all canyon surfaces. The sensible heat was transferred mainly from the canyon surfaces to the ambient air, but also from the air to the ground in the morning. The effective albedo of the canyon had a diurnal value of 0.20–0.25, but dropped to 0.10 in the afternoon when the ground strongly transformed the direct and reflected solar radiation into sensible heat. This narrow street configuration enhanced solar radiation absorption and longwave radiation trapping.     

燃气冷热电三联供项日前期论证评估体系的建立

对燃气冷热电三联供项目进行前期论证是非常重要的。本文根据国家政策和三联供项目应用情况,采用模糊综合评估法,构建了项目前期论证评估体系;可辅助决策者从战略高度评价燃气冷热电三联供项目的可行性、选择项目的启动时机。     

燃气冷热电三联供项目前期论证评估体系的建立

对燃气冷热电三联供项目进行前期论证是非常重要的.本文根据国家政策和三联供项目应用情况,采用模糊综合评估法,构建了项目前期论证评估体系;可辅助决策者从战略高度评价燃气冷热电三联供项目的可行性、选择项目的启动时机.     

An innovative framework for determining the damage probability of equipment exposed to fire

When considering a quantitative risk assessment of domino effects in chemical process facilities, the Damage Probability of equipment exposed to Fire (DPF) is a key element. In this paper, an innovative framework is proposed to determine the DPF, and the approach is demonstrated using a vertical plate. Being different from the current Probit model, structural reliability methods are applied to a pre-established lumped temperature model to obtain the DPF. Moreover, the static and dynamic DPF are distinguished, where the static one is obtained through the first-order reliability method and response surface method with an innovation in the pre-analysis of stable state to derive the limit state equation, while the dynamic one is obtained solving the Kolmogorov backward equation using the finite difference method based on stochastic diffusion process and first passage failure theories. The vertical plate demonstration shows the feasibility and availability of the proposed framework. A more practical case study with a horizontal LPG tank is also discussed to validate the suggested approach.     

既有建筑结构体系可靠性评估实用方法

回顾和总结了结构可靠度理论的发展历史以及既有建筑结构评估的研究现状,指出现有结构体系可靠性评估方法的不足.针对存在的问题,提出了基于子结构的既有建筑结构体系可靠性评估的简化方法,建议将子结构取为自然层,先对子结构进行可靠性评估,再根据子结构评定结果,通过结构自然层间的相关关系对结构体系可靠性进行评估.根据层次分析法,提出了一种适合工程应用的子结构中构件权重系数实用计算方法.工程实例分析结果表明,所提方法得出的评定结果能更好地符合实际情况.     

Structural analysis of Pareto-optimal solution sets for multi-objective optimization: An application to outer window design problems using Multiple Objective Genetic Algorithms

In single-objective optimization problems, with only one optimal design objective, the absolute optimal solution to maximize/minimize the objective function can be determined. However, in most real design problems, the optimization problems are multi-objective, where two or more independent design objectives must be optimized simultaneously, and no single absolute optimal solution necessarily exists. In these cases, it is helpful for designers to recognize the range of alternative solutions that exist in Pareto-optimal sets and choose an acceptable solution from among them. In this paper, the authors carried out multi-objective optimization using Multiple Objective Genetic Algorithms through a real case study involved in indoor environmental design – the design of outer windows. Then the authors analyzed structure of Pareto-optimal solution sets. Here we present the analysis process as well as the case study details, and show how the method proposed here is effective at finding an acceptable solution for multi-objective optimization problems.     

一种城市热环境质量评价方法——空气焓变质量指数

由于城市热岛效应,使得市内温度比郊区高,城市热环境相对郊区差。本文试以温度为基础而引入“焓变”作评价指标,提出空气焓变质量指数为评价方法,描述城市热环境质量。     

Sectors associations and similarities in input-output systems: An application of dual scaling and fuzzy logic to Canada and the United States

Various authors addressed interindustry linkages in the context of input-output systems, however many focused on the identification of key sectors in the economy. Sonis et al. (1996) offered as a field of influence theory an alternative approach focusing on the analytical importance of elements and combinations of elements. In an attempt to further the understanding of the linkages in an input-output system, the objective of this paper is to examine the cluster structure of sales and purchases profiles when the principle of excluded middle is violated by the use of fuzzy sets. The identification of fuzzy clusters is based on an analysis to derive an alternative decomposition ofinterindustry flows (Dridi and Hewings 2002), it is a complementary approach to the so-called Matrioshka principal (Sonis and Hewings 1990) and will be presented first; the approach looks into the hierarchy of the statistical dependence between supply and demand in input-output systems. The analysis on the cluster structure and the interindustry flows is conducted using the data analysis technique known as dual scaling (Nishisato 1980, 1994). Results of the analysis will be illustrated using input-output tables of the US and Canada. An earlier draft of this paper was presented at the 41st Annual Meeting of the Western Regional Science Association-Monterey, California (February 17–20, 2002), comments from conference participants, J. Le Gallo, and two anonymous referees are acknowledged. The usual disclaimer applies.     

一类新复合形法及其在临界滑动面搜索中的应用

针对广泛采用的基本复合形法存在着搜索不完全、映射系数取值不灵活、复形多样性保持差等缺陷,提出了相应的改进措施,如动态全域映射收缩算子以及最大冗余点映射准则,形成了一类新型的复合形法。在确定冗余点时综合考虑了距离空间和目标函数值两方面的信息。通过对某复杂土坡的最危险滑动面的搜索表明,新型复合形法的寻优成功率比基本复合形法大大提高。     

建筑结构"中震可修"性能指标的确定方法

本文以结构顶点位移作为结构的性能参数,综合考虑结构物理状态以及经济效益双重标准,确定结构“中震可修”的性能指标。目的是把我国现行建筑抗震设计规范中“中震可修”由定性描述转化为定量描述,方便在实际设计中应用。同时也为实现基于性能抗震设计提供基础研究。