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.     

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.     

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.     

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.     

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.     

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。     

一种用于已知频率信号的无相移数字滤波方法探讨

提出了一种用于当有效信号的频率已知或可求得时的数字滤波方法。讨论了该方法的滤波原理、精度．并给出了计算机模拟滤波程序及其处理结果．通过实验验证．该方法的滤波效果良好．     

预应力构件应力损失的产生及减损方法分析

混凝土是应用最为广泛的施工材料,在房屋、桥梁、公路等工程项目中与受弯构件相配合。因为混凝土具有较低的极限应变与抗拉强度,应力构件施加压力给混凝土,对荷载之后的拉力做抵消,是有效控制裂缝的方式。     

A new methodology for damage assessment of bridges through instrumentation: application to the Sorraia River Bridge

Bridge Management Systems (BMSs) provide an efficient means of manipulating information about a bridge in order that its long-term health is assured and maintenance programmes can be formulated in line with budgetary constraints and funding limitations. However, some weak points remain unsolved and thus limit the possibilities of BMSs. Since accurate material deterioration and damage evolution models are not yet fully developed, one of the weaknesses of a BMS is how to decide when to act and which level of intensity should be used in maintenance/repair/strengthening operations. A high level of uncertainty is associated with the decision of undertaking these operations as the available deterioration models (chloride ingress, carbonation, alkali?–?silica reaction) are still not completely accurate due to the many variables involved (environmental, material, loading). Structural monitoring is a possible way of dealing with such a problem. Normally, in situ measurements have been used just to update deterioration models included in the damage modules of a BMS. However, in this paper a different approach is presented. Data from the instrumentation are used not to feed the damage models, but are directly used in a new module of the BMS, the so-called monitoring/control module with the objective of detecting degradation when incipient so the decision module of the BMS may respond appropriately. This module should perform damage detection in a fast, effective and accurate way. In order to achieve that, a new methodology, Interval Analysis, and a new algorithm were developed. They have been checked in laboratory tests where the potential for damage detection has been compared to other techniques. They are now being applied for the first time in a prestressed concrete bridge in Portugal. The follow-up of this application will be the basis for the adoption of the new monitoring/control module in a Portuguese BMS.     

探索适应轨道交通超常规发展的管线综合规划

上海的轨道交通进入超常规建设状态,对位于市中心城交通繁忙地区轨道交通车站的管线综合,如何适应工程建设需要和兼顾地区交通要求,同时根据地区详细规划将远近期需求相结合,安排好各类管线,通过近几年大量的规划设计实践进行了探索。