Automated multi-objective optimization system for airport site layouts

Airport construction planners often face the problem of identifying optimal locations for temporary construction facilities on site, as the planned locations of these facilities usually influence important and conflicting planning objectives such as improving the efficiency of construction operations and maintaining safety on site. Careful evaluation of all feasible locations for temporary facilities and the selection of an optimal layout are needed in order to achieve these multiple important objectives. This paper presents the development of a practical automated system to optimize multiple conflicting planning objectives and provide all possible optimal tradeoff solutions among these objectives. The system is implemented and integrated in four main modules: (1) a comprehensive multi-objective optimization engine that integrates and optimizes construction work zone safety, construction-related aviation safety, construction-related airport security, and all relevant site layout costs; (2) a relational database that integrates planning data and stores all the generated optimal solutions; (3) an Input/Output module to facilitate specifying planning and optimization parameters and retrieving the generated optimal site layout solutions; and (4) a visualization module that communicates with external CAD software in order to support the visualization of the generated optimal site layout plans.     

‘CHASTE’: construction hazard assessment with spatial and temporal exposure

CHASTE—‘Construction Hazard Assessment with Spatial and Temporal Exposure’—is a conceptual model that enables forecasting of safety risks in construction projects for different trades, at appropriate levels of detail and reliability for different planning windows and managerial purposes, in a highly automated fashion. Unlike earlier models, CHASTE explicitly accounts for the fact that construction workers are frequently endangered by activities performed by teams other than their own. The risks to which workers are exposed change through time, as the activities performed and the physical environment of construction sites change. CHASTE uses a knowledge base of construction activities and probabilities of loss‐of‐control events, coupled with a project’s construction plan and a digital building model, to forecast risk levels for work teams. It has been implemented in prototype software and tested on two projects.     

Optimizing the utilization of multiple labor shifts in construction projects

Evening and night shifts are often used in construction projects to accelerate schedules despite their negative impacts on construction cost and productivity. In order to minimize these negative impacts, this paper presents a multi-objective optimization model for scheduling multiple labor shifts in construction projects. The optimization model incorporates (1) an initialization module that initializes the scheduling optimization computations; (2) a scheduling module that develops practical multiple shift schedules and evaluates the impacts of decision variables on project performance; and (3) a multi-objective genetic algorithm module that searches for and identifies optimal/near optimal tradeoffs among minimizing project duration, reducing cost, and minimizing labor utilization in evening and night shifts. An application example is analyzed to illustrate the use of the model and demonstrate its capabilities in optimizing the planning and scheduling of multiple shifts in construction projects while complying with all job logic and labor availability constraints.     

VR-based planning of construction site activities

This paper presents an approach to the integration of site-related activities into the planning and scheduling of the entire construction project. The paper starts by briefly reviewing some common methods used by construction firms in the planning and scheduling of site activities. Next follows a discussion of current research efforts concerned with the modelling of site-related procedures. Then a virtual-reality-based model is proposed, which uses both knowledge-based simulation of the work progress and visualisation capabilities, to achieve the desired integration. Finally the prototype system is described and its potential is demonstrated through several examples.     

Classical Planning Model‐Based Approach to Automating Construction Planning on Earthwork Projects

Extensive research in automated operation planning has led to significant advances in the area of robotics. Theories and methods resulting from robotics have yet to be adapted to enable automated project planning in construction engineering. Aiming to demonstrate the potential of implementing automated planning theory and methods in construction project planning, we developed an automated earthwork planner prototype following the principles and framework of classical planning model in computer science. As time is not explicitly represented, implementing classical planning model to perform optimization and planning simultaneously results in potential temporal–spatial conflicts (TSCs). The present research develops a two‐step approach to separate operations optimization and earthwork planning in typical rough grading projects. As such, TSCs encountered in existing mathematical programming based earthwork planning methods are resolved. To enable fully integrated and automated earthwork planning, the prototype system has been seamlessly integrated with project scheduling and operations simulation software for higher level analyses. To demonstrate advantages of the automated planning methodology, construction plans were independently produced by 14 graduate student teams on the same “testbed” project; results were evaluated and compared with the plan generated by the proposed system.     

Construction equipment productivity estimation using artificial neural network model

Estimating equipment production rates is both an art and a science. An accurate prediction of the productivity of earthmoving equipment is critical for accurate construction planning and project control. Owing to the unique work requirements and changeable environment of each construction project, the influences of job and management factors on operation productivity are often very complex. Hence, construction productivity estimation, even for an operation with well‐known equipment and work methods, can be challenging. This study develops and compares two methods for estimating construction productivity of dozer operations (the transformed regression analysis, and a non‐linear analysis using neural network model). It is the hypothesis of this study that the proposed neural networks model may improve productivity estimation models because of the neural network's inherent ability to capture non‐linearity and the complexity of the changeable environment of each construction project. The comparison of results suggests that the non‐linear artificial neural network (ANN) has the potential to improve the equipment productivity estimation model.     

A simulation optimisation tool for planning of low-income housing projects

Construction of low-income housing projects is a recurring process and is associated with uncertainties that arise from the unavailability of resources. This paper presents a case study that discusses how computer simulation and optimisation are used to aid government agencies and/or contractors in planning of such projects. It illustrates the optimisation of project objectives, taking into consideration the interaction amongst involved resources. As such, total duration and the associated total costs, including direct and indirect costs, can be estimated and optimised. One Youth Habitation project that is executed in 6th of October City in Egypt is analysed in a step-by-step procedure to demonstrate the capability of proposed computer simulation and optimisation prototype (named LIHouse{_}Sim) in the modelling construction of low-income housing projects using bearing block walls with hollow core technique. The presented tool proves its practicality to contractors in estimating the time and costs of the recurring process of low-income housing construction, considering complex interdependencies between construction resources and the uncertainties associated with construction activities. The LIHouse{_}Sim prototype is used to perform a wide analysis for the alternative of the effective optimisation criteria in the bearing block walls/hollow core technique and for the genetic algorithm optimisation approach elements.     

Project understanding,planning, flexibility of management action and construction time performance: two Australian case studies

Construction time performance (CTP) and flexibility in approaches to project time planning have been shown to be significantly associated. This raises interesting questions about how effective planning and control to facilitate flexibility in overcoming unexpected problems may be achieved. Case study data were used to explore links between planning and flexibility. This paper reports upon a recent study of two highly complex projects, a mental and forensic health hospital and a very large freeway/bridge/tunnel urban infrastructure project. The authors investigated planning flexibility using a framework of project team understanding and knowledge transfer to provide a model that contributes to our understanding of mechanisms and drivers that delivers flexible behaviour that may affect CTP. We conclude that both ability, supported by organizational and team competence, and commitment to explore construction method options in a flexible manner, i.e. responding to unanticipated problems, are necessary to facilitate good construction time performance.     

“麻雀虽小,五脏俱全”廉租房项目户型设计浅析——以福州远东丽景社会保障房（廉租房）项目为例

本文以福州远东丽景社会保障房项目为例,着重从规划和廉租房建筑单体户型设计两个方面进行分析,提出紧凑性、实用性、精细性、经济性的户型设计理念,并结合具体项目的设计实践,希望对我国目前还处于廉租房建设起步阶段背景下的廉租房建筑设计起到借鉴作用。     

房屋建筑项目管理成熟度模型研究

在借鉴已有的项目管理成熟度模型的基础上,结合房屋建筑项目的实际情况,构建房屋建筑项目管理成熟度模型.然后,结合项目管理知识内容和实际情况,构建了房屋建筑项目成熟度的评价指标体系,并应用模糊综合评判方法计算项目管理成熟度的值.为房屋建筑项目管理能力的评价提供了参考.     

产学结合:开发以BIM为基础的设备、电气、给排水和消防专业协同教学单元

作者采用产学结合的方式,致力于开发出一种教育单元原型,以用于对学生进行最优化BIM[1]使用的教学。这种优化使用方法基于施工管理流程,有利于协调设备、电气、给排水和消防(MEPF)的设计安排。基于一家著名建筑公司的先验基础,该教育单元原型强调了在统筹复杂的、真正的项目方面所吸取的经验教训,并整合了亲身实践的互动实践经验。作者记录并讨论了模型的创建过程,力求同时在理论和实践上解释BIM。本模块通过采用流程图,重要事件、动态三维模型以及通过互动练习的方式来对BIM工作流程进行审慎评估。作者采用了屏幕录制软件Adobe Captivate及大量其它的BIM工具,并结合演示视频强调了由不同专业的项目团队成员开发的几个BIM模型的组装、绘图和外观检查。交互式的课外作业使得学生对MEPF硬件和软件的冲突检查和协调问题进行探讨。这些作业促使学生经过认真思考后查明来源,消除冗余,并为各种冲突现象制定出解决方案。后继工作将尽力促进对MEPF专业协同教学模块的扩大与发展,并开发其它与BIM相关的特定领域的教学模块。     

OPIS: An Object Model–Based Project Information System

Abstract: Future computer-aided project management (CAPM) software will be greatly improved through the technologies of project modeling—the rich, general-purpose representation of the project in the computer—and system integration—the sharing of computer models among applications. Our approach is to achieve system integration by establishing standard models that all applications can adopt and share. This requires a standard data model that specifies the general data-representation approach, a standard domain model that provides a schema or language for representing construction information, and a project model or database for information about a specific project that can be shared among multiple computer applications. This paper reviews these standard models and then describes our prototype integrated system called the object model–based project information system, or OPIS. OPIS uses a shared object–oriented database as the central unifying core of an integrated project planning system that includes an interface to an intelligent CADD program, a plan-generation expert system, an estimating application, and a scheduling application. OPIS demonstrates the feasibility and power of using standard object-oriented project models to achieve CAPM system integration.     

Construction delay analysis techniques

Construction projects continue to suffer delays. Things go wrong and the project's completion date gets pushed back, with someone to be blamed for it. In practice, attempts are made to identify the causes of delays and schedules are modified to incorporate revised duration and new project time. The analysis itself is usually complex and can be aided by a computerized approach. This paper discusses different delay analysis techniques that are currently used by practitioners in the construction industry. It also discusses a proposed new delay analysis technique called the Isolated Delay Type (IDT). These techniques were tested against a case example and their strengths and weaknesses highlighted. The new technique can be used as a standalone module for delay analysis or could be incorporated within a computer system for construction delay analysis and claims preparation called Computerized Delay Claims Analysis (CDCA) that integrates different software including an expert system and management software such as scheduling and a database or spreadsheet.     

Using fuzzy multiple criteria decision making approach to enhance risk assessment for metropolitan construction projects

The undertaking of construction projects in metropolitan areas is a risky, competitive, and dynamic proposition requiring a reliable risk assessment model for adequate planning. This study employs a fuzzy multiple criteria decision making (FMCDM) approach to systematically assess risk for a metropolitan construction project. Consistent fuzzy preference relations (CFPR) are used to measure and investigate the relative impact on project performance of twenty identified risk factors included in four risk dimensions. The fuzzy multiple attributes direct rating (FMADR) approach is employed to analyze the occurrence probability of multiple risk factors. Furthermore, the level of risk for the overall project caused by individual risk factor is evaluated with the synthesized analysis of the relative impacts and probability of occurrence. The implementation of FMCDM makes the proposed risk assessment approach more reliable and practical than the traditional statistical approach. The proposed approach can be employed to effectively evaluate the overall project risk, and can be benefited to efficiently identify significant risks of a metropolitan construction project.     

工作分解结构(WBS)原理在房建工程信息编码系统中的应用

在房建工程项目数字化管理中借鉴工作分解结构(WBS)原理进行信息编码系统设计,即在编码系统基础上建立数字模型,以推进项目管理精细化。结合工程实践,阐述运用WBS原理设计开发房建工程的WBS编码系统,使WBS在项目成本、进度、质量以及BIM模型技术方面的数字化应用更有实用性并提升管理效率。     

工程项目施工规划与造价管理分析

本文通过工程项目施工规划的分析,提出在施工规划时考虑合理有效措施加强造价管理的理念,以达到事前控制造价的目的,强调运用这种理念对工程项目降低施工成本,控制工程造价的重要意义。     

虚拟施工的BIM应用:三大高校合作项目

越来越多的设施业主要求项目组移交竣工BIM模型,以便用于建筑的运营和维护。根据项目要求的不同,业主可能将竣工模型建立与移交的责任指派给总承包商。因此,施工队伍的各成员不但越来越需要熟悉BIM建模软件的应用,还需熟悉利用可靠的设施信息支持完整BIM的必要业务流程。竣TBIM模型的创建,要求承包商首先要基于建筑师、工程师和顾问等设计师所提供的图纸和信息的基础上,创建建筑,结构和设备模型。这要求承包商的组织机构内要有一名人员具备各与专业设计模型相关的技能和知识。一旦设计模型被创建(或重新创建),承包商可将这些模型用于开发施工用的BIM模型。一个完整的施工模型通常包括:成本估算,施工进度计划、冲突检测与分析以及现场物流。业主对设施管理用竣工模型提出新增要求,包括添加运营和维护用的具体数据。本文所述项目旨在为了更好地了解,在为业主实施BIM的项目上,承包商对项目所起作用的复杂性。为实现此目标,三所大学合作建立了数个校际团队,从每所学校各抽调一名学生分配至三个团队的一个,充当BIM商业建筑项目BIM应用里的承包商角色。本文从两个方面汇报项目的挑战和细节:导师——项目组织、学习目标和策略,学生——项目组织、团队合作过程以及策略。     

Selection of mobile cranes for building construction projects

The complicated process of selecting cranes for construction projects can be divided roughly into two main phases: (1) a general decision on the type of crane, mobile or tower; and (2) selection of the particular model according to the required size and technical specification. Several determinants of this second phase of the selection process in a typical mobile crane culture were investigated through on-site interviews with representatives of major construction companies. Factors affecting mobile crane selection were identified, classified, and rated according to their degree of influence. The involvement in equipment planning and crane selection was characterized with regard to project stages and planning parties. The findings were analysed with a view to the changing participation level of each party throughout project life. The conclusions of the study portray a picture that is different from the common assumptions about mobile crane selection, with respect to both influencing factors and the process itself. The study underlines the weight of non-project-specific factors, and shows that equipment planning is not merely a one-time technical exercise executed by a planner, but rather a process carried out throughout project life by a joint effort of several parties.