Schedule-dependent evolution of site layout planning

The appropriate layout of temporary facilities on a construction site has a large impact on construction safety and productivity. For the duration of a project the site layout may need to be efficiently re-organized at various intervals to satisfy the schedule requirements and to maintain site efficiency. This paper presents a practical model for schedule-dependent site layout planning in construction. The proposed model uses a combination of artificial intelligence tools (knowledge-based systems, fuzzy logic, and genetic algorithms) to generate, optimize, and re-organize the site layout plan at frequent intervals during the project. The model incorporates flexible representation of irregular site shapes and several options for placing facilities. Based on the proposed model, an automated system is developed, fully integrated with widely used scheduling software. At each schedule interval, the system recalculates the space requirements and, for the convenience of congested sites, can utilize parts of the constructed space to accommodate temporary facilities. Details of the schedule-dependent model are described, and its application in an actual case study project is presented to demonstrate its capabilities.     

A decision-making system for construction site layout planning

A decision-making system, which consists of input, design, evaluation and selection, and output stages, is proposed to solve dynamic, multi-objective and unequal-area construction site layout planning (CSLP) problem. In the input stage, the multiple objectives, schedule planning and site condition are determined. In the design stage, two mathematical optimization models max-min ant system (MMAS) and modified Pareto-based ant colony optimization (ACO) algorithm are employed to solve single objective optimization (SOO) and multi-objective optimization (MOO) problem respectively. In the evaluation and selection stage, the intuitionistic fuzzy TOPSIS method is used to evaluate and select the best layout plan among the generated layout alternatives from the design stage. The performance of the proposed decision-making system, which was verified by a residential building project, shall assist the practitioners in the construction industry to deliver construction projects in a more efficient and effective manner, and thus construction costs could be reduced significantly.     

Cost–safety trade-off in unequal-area construction site layout planning

Cost and safety are two key elements when designing a good construction site layout planning (CSLP). Previous research works always considered CSLP from the aspect of reducing cost and treated SCLP as a single objective optimization problem. In the paper, CSLP was designed by a multi-objective optimization (MOO) model using modified Pareto-based ant colony optimization (ACO) algorithm, which could find a Pareto solution (trade-off layout) to fulfill the requirement of reducing cost and improve the site safety level simultaneously. Furthermore, in order to apply MOO model to solve unequal-area problem, the random grids-recognition strategy was employed in the proposed MOO model to solve the unequal-area site layout problems without increasing the computational complexities. A case study of a residential building project is used to validate the proposed MOO model and the results are very positive.     

Dynamic construction site layout planning using max-min ant system

Construction site layout planning (CSLP) is a dynamic multi-objective optimization (MOO) problem as there are different facilities employed in the different construction phases of a construction project. In this study, a new method using continuous dynamic searching scheme to guide the max-min ant system (MMAS) algorithm, which is one of the ant colony optimization (ACO) algorithms, to solve the dynamic CSLP problem under the two congruent objective functions of minimizing safety concerns and reducing construction cost is proposed. Using weighted sum method the MOO problem can be solved by the proposed MMAS method. An office building case was used to verify the capability of the proposed method to solve dynamic CSLP problem and the results are promising. The approach could be benchmarked by researchers using other advanced optimization algorithms to solve the same problem or expand the applications to other fields.     

基于SLP的建筑施工现场平面布置

为了解决建筑施工现场不合理布局造成的成本和工期问题,采用系统布置设计的方法,对郑州国龙商务中心在建项目的施工现场平面布置进行分析,达到了降低材料二次搬运费等建筑成本的效果。     

兰新客专预制箱梁场地规划布置设计

结合兰新客运专线玉门制梁场的施工实际,从制梁场的规划设计方面入手,对箱梁预制周期及梁场生产能力的确定进行了介绍,阐述了预制箱梁生产区的规划设计要点,以期通过科学、合理的规划布置,达到节约用地、提高机械化施工程度,节能创效的目的。     

A hybrid CAD-based construction site layout planning system using genetic algorithms

The efficient layout planning of a construction site is a fundamental task to any project undertaking. In an attempt to enhance the general practice of layout planning of construction sites, the paper introduces a novel approach for producing the sought layouts. This approach integrates the highly sophisticated graphical capabilities of computer-aided design (CAD) platforms with the robust search and optimization capabilities of genetic algorithms (GAs). In this context, GAs are utilized from within the CAD environment to optimize the location of temporary facilities on site. The functional interaction between GAs and CAD and the details of the GA-based layout optimization procedure are presented. A fully automated computer system is further developed to demonstrate the practicality of the chosen approach. In order to evaluate the system's performance, a local construction project with a 24,000m² site is used. The automated system produced highly satisfactory results and showed notable flexibility through its CAD-based input/output media.     

The application of the ant colony optimization algorithm to the construction site layout planning problem

A good site layout is vital to ensure the safety of the working environment, and for effective and efficient operations. Moreover, it minimizes travel distance, decreases materials handling, and avoids the obstruction of materials and plant movement. Based on studies in the manufacturing industry, the cost of materials handling could be reduced by 20–60% if an appropriate facility layout is adopted. In designing a site layout, a planner will first position the key facilities that influence the method and sequence of construction, and then assign the remaining facilities in the available space that is left over. This process is similar to the positioning of facilities in the ant colony optimization (ACO) algorithm. The general principle of the ACO algorithm is to assign facilities to a location one by one, and the occupied locations are deleted from the location scope in the next assignment. In the study, ACO algorithm is employed to resolve the construction site layout planning problem in a hypothetical medium‐sized construction project. By applying fuzzy reasoning and the entropy technique, the study calculates the closeness relationship between facilities, in which the optimal site layout is affected by the mutual interaction of facilities.     

Performance of global optimization models for dynamic site layout planning of construction projects

Dynamic construction site layout planning is a complex optimization problem that is characterized by nonlinear objectives and constraints, which impose great challenges in obtaining global and feasible solutions. This paper presents and compares between two global optimization models of dynamic site layout planning that were developed to overcome the limitation of previous models in the literature. The first model utilizes Genetic Algorithms (GA) while the second model utilizes Approximate Dynamic Programming (ADP). The performance of these two optimization models is analyzed in terms of the effectiveness of reaching optimum solutions and the efficiency of reducing the computational time. This analysis is performed using a designed set of problems of dynamic site layout planning with changing size and complexity. It was found that ADP outperformed GAs in terms of effectiveness and efficiency. However, GAs still prove to be a viable optimization tool because of its simplicity and multi-objective optimization capabilities.     

A tri-objective ant colony optimization based model for planning safe construction site layout

Realizing safety improvements in construction site layout planning (CSLP) is vitally important to construction project safety management. Unlike previous studies in which the safety objective is built without detailed risk factors analysis, this study transforms CSLP into a multi-objective optimization (MOO) problem with designing two safety objective functions due to facility safety relationships (potential risks arising from interaction flows) and geographic safety relationship (potential risks arising from hazardous sources) from the holistic interpretation of interaction relationship connecting temporary facilities. Besides, a supplementary cost reduction objective function was also derived as cost is a critical barrier against safety improvement. Subsequently, a tri-objective ant colony optimization based model was developed to solve MOO problem. Finally, a case study is used to verify the proposed model. The study enriches safety implications by considering onsite safety issues from interaction relationship and enhances site safety of CSLP in the pre-construction stage.     

Optimisation of site layout planning for multiple construction stages with safety considerations and requirements

This paper develops a mathematical formulation to model and optimise site facility locations inside a construction site for a construction project's different stages. The existence and dimensions of a construction project's available locations and site facilities can be varied across the construction stages. Without proper planning, unnecessary facility relocations may be required in each construction stage, resulting in a higher construction cost and longer construction time due to the need to dismantle and set up site facilities. Site layout plans should be optimised using a multiple-stage model to avoid unnecessary changes to facility settings across construction stages, improving efficiency. The proposed site layout problem with multiple construction stages is formulated as a binary-mixed-integer-linear programme, which can be solved by a standard branch-and-bound algorithm using the commercial software package LINGO. The mathematical objective function established in the solution process aims to minimise the total cost, which consists of the material transportation cost between the relevant site facilities and the dismantling, setup and relocation costs for all of the involved site facilities in each construction stage. Numerical examples using the proposed mathematical model to optimise different site layout settings for a construction site are given, including (1) a reference site layout plan using the conventional static single-stage approach, (2) a multiple-stage construction site layout plan and (3) a multiple-stage site layout plan with additional safety design considerations.     

Simulation analysis of site design and layout planning to mitigate thermal environment of riverside residential development

The present study explains the application of a numerical simulation to investigate the thermal environment of a new riverside residential development in summer. The case study area consists of more than one hundred two-story detached houses built next to a river near Tokyo, Japan. According to the meteorological data, prevailing wind directions are at an angle to the northbound river flow affecting the microclimate of the study area in terms of surface temperature of land and buildings, air temperature and wind distribution at pedestrian height. These factors have been estimated using the stepwise CFD (computational fluid dynamics) simulation of radiation, conduction and convection. This method leads to an improvement of outdoor thermal environment by manipulating the site design and layout planning scenarios. The effect of river, permeable pavements and green space on thermal environment is examined by the site design options. Likewise, the impact of building arrangement is evaluated using alternative layout planning scenarios. In total, five scenarios have been simulated for the proposed sustainable development as explained in the paper. Above simulations provided an insight into the mitigation effects of each countermeasure. It is also shown that the management of inflow paths and the creation of wind paths for the interior of the site have the potentials to improve the outdoor thermal environment of riverside residential development.     

谈太原市小学规划布局

百年大计,教育为本。教育是民族振兴、社会进步的基石,是提高国民素质、促进人的全面发展的根本途径,强国必先强教。以太原市小学为例,分析其现状建设情况,结合城市改造和规划,提出规划布局的相关建议,以期对太原市现行教育设施建设标准的提升有所裨益。     

商业住宅小区房间布局规划与设计

从住宅小区内商业空间设计研究的必要性出发,阐述了目前商业住宅小区建筑设计存在的问题,针对住宅小区内商业现状,提出了关于现代商业住宅小区内房间布局与空间设计的几点建议,以满足人居环境的需求。     

施工现场平面布置方法及要点

根据以往工程的施工经验,介绍了施工现场平面布置的依据、原则和主要内容,及施工现场平面布置中塔吊、施工电梯布置等方面的注意要点,以期指导实践。     

Repertory grid technique in the development of Tacit-based Decision Support System (TDSS) for sustainable site layout planning

Site layout planning is a significant but relatively ignored work on construction site, which has been treated improperly as somewhat routine. It is known that the complex interrelationship of material, equipment, laborers, space, environment, assess road, surrounding buildings, and building types affect the productivity and efficiency of a construction process. This complexity was inhibiting the smooth flow of resources especially when many trade contractors were working simultaneously on site. The study aimed to extract a set of core factors in site planning focusing on the tacit knowledge acquisition process to develop a Tacit-based Decision Support System (TDSS). A combination of the repertory grid technique and open-structured interviews was conducted for the tacit knowledge acquisition process. Cluster analysis and repertory grid analysis on the extensive responses from a structured interview were conducted. A computer program entitled “TDSS” was developed as a flexible tool to assist both senior and junior site layout planning engineers.     

面向可实施性的商业设施布局规划

在剖析当前商业设施规划建设存在问题的基础上,以浙江省江山市为例,探讨了消费时代商业设施规划的新框架,并从疏理商业规模、明确商业体系结构、实现图则控制引导等方面,提出了其规划编制思路,旨在将城市商业发展的控制要求落实到用地层面,实现商业规划的可操作性。     

吕梁市城市天然气场站布置规划应用

对建设城市天然气场站的必要性进行了分析,介绍了站址的选择原则,并结合实例,阐述了门站的规划、布置及工艺流程,着重研究了CNG加气站的设置方案,并指出合理布局天然气站场,利用天然气,对调整能源结构、解决大气环境污染问题具有重要意义。     

探析场地设计

场地规划设计,是建筑设计和城市规划领域中十分重要的环节,是一个涉及到社会、文化、技术、美学等诸多方面的重要领域。本文从地形差异、用地差异、使用群体差异、工程项目差异四个方面来描述场地设计,以期通过场地设计营造良好的城市空间环境。