临朐县城镇密集地区统筹产业发展与布局研究

从统筹区域产业发展与布局的角度,探讨了生态环境良好的临朐县城镇密集地区如何通过理顺产业发展方向、优化产业布局,促进经济效益和环境效益双丰收,并指出了指导性建议,对促进该县经济发展具有重要意义。     

Measuring surplus capacity for multiobjective optimal design of foul sewer systems

ABSTRACT

This paper proposes a new performance index of foul sewer systems, i.e. sewer conveyance capacity (SCC) index, to quantify the surplus capacity for multi-objective optimization design problems. The use of the new SCC index is demonstrated using a hypothetical network and a real-world foul sewer network. Results obtained show clear trade-offs between SCC and the other two objectives considered, i.e., capital and operational costs and greenhouse gas emissions. The results show that the upstream sewers in the system often have a relatively large surplus capacity, while the sewer mains operate close to the design capacity. Moreover, SCC is compared with three common indicators at both individual sewer and system-wide levels. Strong correlations between SCC and other indicators are revealed, implying that SCC is a good representation of system performance and can provide a more comprehensive picture of the foul sewer system performance.     

An integrated approach to the layout and design of water distribution networks

A model for the least cost layout and design of looped water distribution networks has been developed. The model consists of two linked linear programming formulations. One linear program determines the least cost layout of a looped distribution network given an initial pressure distribution. The other model determines the least cost component design given an initial flow pattern or pipe layout. The linkage between the two linear programs is provided by the use of output from one linear program as input to the other. Since the constraints in the layout model may provide looping without ensuring true redundancy in the system, a layout review is necessary after solutions of the layout model. If true redundancy is not present a set of ‘optional’ constraints can be applied and the layout model solved again. The procedure is demonstrated by application to a sample network.     

高速公路服务区设计新思路

以京承高速公路巨各庄管理中心项目为例,介绍了高速公路服务区的设计与布局,提出了以一套主要服务设施承担服务区基本功能的设计思路,以期在节约投资的同时,实现高速公路服务区服务效率的最大化。     

Reliability-based design optimization using convex linearization and sequential optimization and reliability assessment method

In this study, an effective method for reliability-based design optimization (RBDO) is proposed enhancing sequential optimization and reliability assessment (SORA) method by convex linearization. In SORA, reliability estimation and deterministic optimization are performed sequentially. And the sensitivity and function value of probabilistic constraint at the most probable point (MPP) are obtained in the process of finding reliability information. In this study, the convex linearization is constructed by utilizing the sensitivity and function value of the probabilistic constraint at the MPP. So no additional evaluation of the probabilistic constraint is required in the deterministic optimization in SORA. The proposed RBDO method is applied to numerical examples and compared to various RBDO methods. It is shown that the proposed method is very efficient with similar accuracy.     

Current and future use of systems analysis in water distribution network design

Computer use in the design of water distribution networks was inititated through the use of network analysis techniques to determine system performance in terms of heads and flows. The last fifteen years, however, have seen the introduction of systems analysis optimization techniques to the range of computer models available for network design purposes. These optimization models differ markedly from the ‘traditional’ network analysis models in that they ‘design’ systems for specified loading conditions rather than just analysing the performance of predetermined systems under given loading conditions. Cost was the primary or only objective in almost all these early optimization models. Water distribution network design has, however, a number of other important objectives, such as maximizing reliability. Issues related to reliability concern include probability of component failure, probability of actual demands being greater than design values, and the system redundancy inherent within the layout of the network. The joint characteristics of these aspects of reliability are not well defined, and as a result no acceptable statement of overall distribution network reliability is yet available. The implications of these issues on each other and the design process as a whole are examined in detail. It is asserted that future work into the application of systems analysis techniques in general, and optimization models in particular, to the design of water distribution should be directed at the resolution of these issues. It is also claimed that the role of computer graphics in such models is not simply as a medium for displaying input parameters and output results such as head contours and flows in a clear graphical form. A more appropriate application of computer graphics is as a means for displaying parameters and characteristics of the reliability and redundancy such that the designer can ‘convert’ the available but inexact measures of these issues into practical statements of system performance.     

Reliability-based optimization of structural systems by adaptive target safety – Application to RC frames

Reliability-based design optimization (RBDO) aims to find the best compromise between cost reduction and safety assurance. Traditionally, component optimization is defined by minimizing the structural cost under a prescribed reliability target for a single limit state. However, as structural failure is rarely devoted to only one component, the system approach becomes necessary to deal with realistic applications. In this paper, a methodology for system reliability-based design optimization (SRBDO) is proposed. Instead of specifying identical predefined component targets, the method is based on adaptive target reliabilities for structural components. An updating procedure is included in the optimization process to ensure the required system reliability. The proposed method aims to find the best compromise between satisfying the target system reliability and optimizing the component performance. The application to reinforced concrete structures shows the interest of the adaptive target reliabilities as well as the efficiency of the updating procedure.     

Reliability-based vector nonstationary random critical earthquake excitations for parametrically excited systems

The study considers the earthquake response of stack-like structures subjected to simultaneous action of random horizontal and vertical earthquake acceleration components. The governing equation of motion in this case is approximated by a set of coupled randomly time varying ordinary differential equations. The components of earthquake accelerations are modelled as nonstationary Gaussian random processes that are obtained by multiplying deterministic modulating functions with partially specified stationary random processes. Specifically, it is assumed that the matrix of power spectral density (psd) functions of the stationary components is not known, while, the variance, average rate of zero crossings, entropy rate and frequency range of interest are taken to be known. The unknown input psd matrix is determined such that the reliability index associated with a specified structure performance function is minimized. The solution procedure employed, combines the theory of Hasofer–Lind reliability indices, response surface modelling and constrained nonlinear optimization tools. The critical input psd matrix so obtained leads to the definition of excitation models that produce the least favorable response, which, at the same time, possess a few of the well known properties of earthquake loads. A numerical example that illustrates the concepts developed with reference to a chimney structure is provided.     

Reliability-based fatigue design of wind-turbine rotor blades

A probabilistic model for analysis of the safety of a wind-turbine rotor blade against fatigue failure in flapwise bending is presented. The model is based on a Miner's rule approach to cumulative damage and capitalizes on a conventional S–N curve formulation for fatigue resistance in conjunction with a new ‘distorted Weibull' distribution for representation of wind-induced bending moment ranges. The model accounts for inherent variability and statistical uncertainty in load and resistance, and model uncertainties are also included. The model is applied to an analysis of the reliability of a site-specific wind turbine of a prescribed make. A 20-year design lifetime is considered. The probability of fatigue failure in flapwise bending of the rotor blade is calculated by means of a first-order reliability method. It is demonstrated how the reliability analysis results can be used to calibrate partial safety factors for load and resistance for use in conventional deterministic fatigue design.     

民用建筑综合管线设计探讨

分析了综合管线设计的重要意义,对施工图的要求和设计方法的选择进行了探讨,全面阐述了综合管线的设计原则,提出综合管线设计应该从经济、适用和美观三个方面达到最优。     

谈老年公寓的设计

从几种国外老年人居住的建筑模式入手 ,结合我国社会实际情况 ,对老年公寓的建筑模式、设计要求、投资现状及发展前景作了较深入地阐述 ,指出修建老年公寓势在必行。     

Reliability-based integrated design of steel portal frames with tapered members

Integrated structural designs, with consideration of system reliability for steel portal frames comprising tapered members, are studied in this paper. The reliability-based integrated design (RID) directly checks the structural system limit states and the corresponding system reliability, based on structural nonlinear analysis. The nonlinear integrated analysis model, the semi-analytical simulation method employed for system reliability assessment, the development processes of RID format and the design application of RID formula and curves are presented in this paper. Design examples and comparisons among three different design formats demonstrate that RID proposed in this paper is of certain and consistent system reliability levels, and provides a feasible way for structural engineers to improve the design quality and flexibility of steel frame structures.     

Reliability-based design of medium mast lighting structural supports

Rural intersections and interchanges often require lighting for driver safety. Although high mast lighting supports, sometimes as tall as 50 m have been installed in many locations, it is becoming apparent that light pollution to nearby residences is an issue. As a response to this problem, the Colorado Department of Transportation is moving towards the use of medium mast lights which are typically 15–20 m in height. This article presents the results of a numerical investigation to develop reliability-based design charts as a function of several key design variables and the mean wind velocity at a site. These medium-mast structures are less than 1 m in diameter at the base and are quite flexible relative to many civil engineering structures. The limit state function is formulated in terms of fatigue life and is computed based on the moments at the base that are produced during multi-mode dynamic excitation as a result of the wind loading. Morison's equation, which provides relative force for slender bodies as a function of flow velocity, was applied within a dynamic finite element framework in order to account for the relative motion between the wind and the motion of the structure. Then, a well-known random vibrations approach was coupled with Miner's rule to estimate the fatigue life of the structural support. Reliability-based design charts for several different design variables such as wall thickness and outside diameter are presented.     

谈变电站总体规划及布置

针对变电站的总体规划及布置进行了阐述,从变电站方位的确定、站区竖向布置、站区边坡支护、防排洪（水）设计及进站道路设计等方面进行了介绍,并结合案例加以说明,为类似项目设计提供了参考。     

平原型生活垃圾卫生填埋场防渗设计与施工管理

介绍了平原型生活垃圾填埋场单层防渗系统的构造形式,并以南北方典型工程为例进行对比,探讨生活垃圾卫生填埋场的防渗设计和施工管理。     

谈模数方法在版式设计中的应用

通过对版式设计及设计方法的概述,介绍了模式及模数体系在设计中的应用,着重分析了网格版式设计及黄金分割法版式设计的应用情况,对提高设计师的工作效率具有积极意义。     

Reliability-based optimum design of reinforced concrete girders

A practical optimization approach to the design of reinforced concrete girders for highway bridges is presented. The approach is entirely based on the American Association of State Highway and Transportation Officials (AASHTO) standard specifications for highway bridges. All behavior and side constraints specified in the AASHTO bridge code are considered in the optimum design process. Two optimization formulations are presented. The first uses load and resistance design factors (LRFD) and the second one is entirely based on a reliability approach. In these formulations, the independent and dependent variables are identified, and the constraints are formulated in both the AASHTO-LRFD format and the AASHTO-reliability-based format. The solutions for both formulations are obtained by using a nonlinear optimization software. Numerical examples illustrate the application of the proposed approach to the design of reinforced concrete T-girders. Sensitivity analyses are also performed for finding the effects of various parameters including steel to concrete cost ratio and allowable reliability level on the optimum solution.     

Optimal design of urban drainage networks

In this paper, a general procedure for the optimal design of urban drainage networks is proposed taking into account realistic technical constraints and the management cost of the automatic flushing devices. The procedure, which is based on the utilisation of a standard genetic algorithm, is first tested with reference to a urban drainage network taken from the literature, while a second test case is considered in order to evaluate the impact of different input parameters and constraints on the optimisation problem. In particular, we evaluate: (i) the effect of considering the crown elevation of the network outlet not fixed a priori but variable in a given range; (ii) the effect of imposing that the size of the conduit downstream a node should be not smaller than the sizes of the conduits upstream; and (iii) the effect of modifying input parameters such as the peak wastewater discharge or the management unit costs.     

总平面设计中减少工厂占地面积的方法

结合多年来从事总图设计的经验，阐述了在总图设计中节约土地的重要性，并介绍了几种在设计中减少工厂占地面积的方法，从而确定最佳的总平面设计。     

城市区域消防资源优化布局研究

安全是城市发展的重要保障和基础底线,消防资源优化布局是提升城市救援能力,保障城市安全的有效手段。针对我国城市目前消防站点覆盖率低、责任分区难划分及消防人员、装备配备结构不完整、不合理等问题,通过科学构建城市消防资源优化及布局模型,对消防站救援响应时间满意度、辖区需求点覆盖防护等级、装备贡献度及人员工作负荷度进行评估,实现消防站优化布局选址、消防救援力量及装备优化配置的模型应用,为新建消防站的选址和现有消防站的救援力量及装备优化配置提供辅助决策。