Decision support for tower crane selection with building information models and genetic algorithms

Tower cranes are major construction equipment that is highly demanded in construction projects. The planning process for tower cranes utilization starts in early stages of the construction projects. Poor selection could incur extra costs on the construction projects or cause delays in project duration. The planning procedures for tower cranes include selection, allocation and operation. This paper presents a framework for the selection of tower cranes types and locations at construction sites. The framework considers three main models: 1) decision making model to select the tower crane type, 2) optimization model for the selection of the ideal number and location of tower cranes, and 3) 4D simulation model to simulate tower crane operations. Several clash detection scenarios are presented to assure the safety operation of the tower crane group. A case study is shown herein to demonstrate the capabilities of the developed framework.     

An integrated decision support model for selecting the most feasible crane at heavy construction sites

Heavy industrial projects, especially oil refinery facilities, consist of numerous components such as modules and vessels, which are large, heavy, and long objects. The successful completion of these projects requires precise planning and selection of safe and efficient single- and/or tandem crane lifts, which are strongly influenced by the crane types and models used. Thus, selecting not only the best crane type and model, but also the most efficient crane operation among alternatives, can result in productivity and safety improvements. In this respect, this paper proposes an integrated decision support model which designs, simulates, and evaluates potential crane operations in accordance with feasible crane types and models based on equipment, cost, site, and environmental aspects of the project. The proposed methodology consists of two components: (1) 3D-based crane selection simulation, which enhances the process of crane selection by not only accurately verifying and identifying engineering factors, but also analyzing feasibility (procedures) of tandem and single-crane operations, from crane installation to lift completion and disassembly of the crane configuration, in a 3D environment; and (2) a crane selection matrix which calculates the crane evaluation scores by measuring various factors of each feasible crane against the project criteria and constraints. The methodology is tested in a case study in order to illustrate its effectiveness.     

Bauen im Strom: Grundinstandsetzung der Wehranlage Kachlet nach 100 Jahren Nutzung

Building in the river: major maintenance of the Kachlet weir system after 100 years of operation The Kachlet weir system is one of the largest weir systems on the German Rhine-Main-Danube waterway and is reaching a 100-year service life. In order to ensure the continued navigability of the Danube, a major overhaul will be carried out in which the weir base will be preserved, the piers upgraded and the weir superstructure and hydraulic steelwork as well as the technical equipment completely renewed. New approaches are being considered for this particular challenge, especially in terms of construction logistics. As a construction aid for the planned construction project, a portal crane system will be erected above the weir system, which will enable the project to be carried out with a high degree of prefabrication and, as a result, a comparatively short construction period. However, the portal crane system also brings new challenges with it, that need to be taken into account during planning.     

如何合理布置塔吊使工程顺利高效进行

根据实际结合塔吊在高层建筑施工中的广泛应用,介绍了高层建筑在施工中如何选择和合理布置塔吊,以保证工程顺利高效进行,可供工程技术人员和施工组织人员参考借鉴。     

A fuzzy logic approach to the selection of cranes

This paper presents a fuzzy logic approach to select the best crane type in a construction project from the main crane types, namely, mobile, tower and derrick cranes. Each factor of the project is classified as being dynamic or static according to whether the factor does or does not depend on the particular project. Linguistic information about the suitability of each crane type with respect to each factor of the project is translated into either fuzzy sets (for static factors) or fuzzy if–then rules (for dynamic factors). The fuzzy rules are then aggregated into a fuzzy relation between the space of factor property and the space of crane efficiency. In a particular project the experts describe the property as well as the relative importance of each factor. The rules are then fired using the max–min extension principle, and the resulting efficiencies are aggregated with their importance weights. The process identifies the best crane as the one with the highest expected overall efficiency.     

Productivity and CO2 emission analysis for tower crane utilization on high-rise building projects

Cranes maintain a central role in construction projects, and tower cranes are one of the major equipment used in the construction of high-rise buildings. As the scale of construction projects increases, selecting a proper crane becomes more important for the successful completion of projects, especially in regards to taller buildings. To provide lift engineers with a planning tool, this paper presents a crane selection methodology for high-rise building construction projects based on crane productivity performance, carbon footprint impact and simulation process. The crane productivity analysis considers a tower crane with two jibs that operates using propellers mounted at the end of each jib to improve the performance of crane operations. This paper presents a methodology to quantify and assess the environmental footprint (CO₂ emissions) associated with the tower crane swing operation. A case study is presented to demonstrate the effectiveness of crane productivity and CO₂ emission analysis for building construction projects.     

Transformation of a 4D product and process model to generate motion of mobile cranes

Modeling and visualization of motion of mobile cranes enable project engineers to identify possible spatial conflicts related to cranes prior to actual operation on job sites and hence, could minimize hazardous conditions and delays associated with spatial conflicts. Current tools for visualizing equipment motion in three dimensions (3D) and across time have limitations due to their reliance on users in modeling a sequence of movement of each piece of equipment experientially and manually. This paper presents an approach for automatically generating motions of mobile cranes to support conflict detection. This approach builds on and extends existing approaches in product and process modeling and visualization of construction operations. It takes a product and process model that contains building design and schedule information of a specific project together with specifications of cranes and construction methods utilized by the project as input. The crane specifications and construction methods constitute project-independent information that describes how cranes should be operated during the execution of activities. The output of the approach is a transformed product and process model that incorporates a set of operations and motions of cranes, which can be used for identifying spatial conflicts associated with crane operations. Validation studies show that the developed approach can be used to model different types of mobile cranes and generate their motion during operations, which enables detection of spatial conflicts related to cranes.     

RT550型越野轮胎起重机

在全球高端市场中,越野轮胎起重机占移动式起重机40%的市场份额。在国内工程机械领域,越野轮胎起重机是一个极具增长潜力的产品。介绍RT550型越野轮胎起重机主要技术参数、系统构成及技术特点。     

品质管理在工程项目管理各阶段的作用和管理特点

对工程项目的质量管理应上升到品质管理的高度上来 ,即不仅仅是按规范要求进行施工质量管理 ,而是按项目的品质定位 ,对项目的整体使用功能、配套条件、耐久年限、抗震等级、设备标准、建材标准、装饰水平、舒适程度、美观程度等进行全面控制管理。品质管理要求从项目的选址立项到规划设计、施工建造、质量验收以及后期养护管理等每一阶段 ,全方位按照品质定位的标准进行分阶段品质目标管理     

Automated Crane Planning and Optimization for modular construction

The majority of industrial projects in Alberta's oil sands are constructed using modular construction. Modules are preassembled components built off-site and transported to the site to be lifted into place with mobile cranes. Heavy lifts include modules as well as major equipment that utilize expensive mobile cranes. Selecting the proper mobile cranes and configurations and finding the best crane position for each lift saves a significant amount of time and cost, while also improving safety. A heavy lift plan facilitates overall site management by reducing extra crane relocations and avoiding dangerous crane clashes. Performing such intensive analysis manually for several hundred lifts and various crane options is a tedious, prolonged exercise. However, no application that carries out such intensive analysis for a number of lifts in modular construction has yet been developed. This paper presents a system, called Automated Crane Planning and Optimization, to automate the above-mentioned analysis for a large-scale project. This system is validated on actual modular projects.     

Evolution of the crane selection and on-site utilization process for modular construction multilifts

Modular construction technology has been used in building construction for decades, having been widely utilized on sites with high traffic volume, restricted accessibility/storage, or business operations which cannot be interrupted by long construction time. A key challenge in this method of construction lies in planning and executing lifts within a short timeframe. In this regard, proper crane selection and site layout optimization can significantly increase productivity and shorten the lifting schedule. This paper thus proposes a methodology for the crane selection process and introduces mathematical algorithms to assess the construction of multi-lift operations. The modular lift process is divided into three stages: crane load and capacity check, crane location, and boom and superlift clearance. Each stage's parameters are introduced, analyzed, and graphically explained. The methodology logic is supported by a generalized mathematical algorithm and is applied and tested on a case study involving the construction of five three-storey dormitories in 10 working days for Muhlenberg College in Allentown, Pennsylvania.     

BIM技术在项目前期策划方面的应用

项目前期策划是全过程项目管理的主要阶段,有效的项目前期策划对建设项目的成本、工期及运作有着积极的影响,是项目建设成功的前提。BIM技术的出现,可能成为克服传统方法弊端和提升策划和决策水平的利器,用来提升社会整体的项目策划能力和水平,以和现代建设项目的高要求相匹配。     

建设领域责任保险体系框架建构设想

以建设项目全生命期为主线,论述建设项目相关参与主体的工作范围和内容,并按照相应的法律规定分析各参与主体在从事项目建设和管理过程中可能承担的民事法律责任,依此设计建设领域责任保险体系框架。     

超高塔垂直运输机械的选择分析

河南省广播电视发射塔设计总高度为388.0m,作为超高结构,其难点在于塔身外围桉叶糖形钢柱的吊装,方案设计分别从超高塔结构施工时垂直运输机械的选择、布置方式、塔式起重机基础、塔式起重机安装和拆除几个方面进行分析,最终采用一台ZSC 50180平臂式塔式起重机作为桉叶糖形钢柱主要吊装工具,布置方式为井道内附着式,同时塔楼顶部安设一台SCM-D300动臂塔式起重机,作为桅杆天线的吊装以及ZSC50180的拆除,满足了吊装需要,为工程顺利进行起到了关键作用。     

浅谈疏浚项目管理中的一些技术措施

结合某疏浚工程实例,就疏浚工程施工前施工设备的选择、施工技术参数的确定以及施工过程中的一些技术措施进行了讨论,通过技术措施的实施,保障了该项目的顺利完工,同时也确保了项目目标的顺利实现。     

A Petri net simulation model for virtual construction of earthmoving operations

A common and extended Petri net simulation framework for virtual construction of earthmoving operations is developed to simulate dynamic changes of workflow and information flow in the earthmoving construction process and illustrate the constraint relationship between various operational equipment and construction restrictions. The proposed framework considers factors that influence earthmoving operations including randomness of construction activities, individual preference of equipment scheduling, and constraint relationship between equipment and construction environment. With the given equipment availability and project indirect cost, the framework can predict construction situation, equipment utilization rate, estimated duration and cost to achieve visualized and intelligent scheduling of virtual construction process in earthmoving operations. The simulation process is conducted on the CPNTools platform. The data required by the research were collected on-site in an actual case. The randomness of construction activities in earthmoving operations and main factors influencing construction are simulated. The sensitivity analysis for the model is carried out. The study will provide technical support and a management basis for equipment scheduling of earthmoving operations.     

Learning from risks: A tool for post-project risk assessment

Risk management (RM) comprises of risk identification, risk analysis, response planning, monitoring and action planning tasks that are carried out throughout the life cycle of a project in order to ensure that project objectives are met. Although the methodological aspects of RM are well-defined, the philosophical background is rather vague. In this paper, a learning-based approach is proposed. In order to implement this approach in practice, a tool has been developed to facilitate construction of a lessons learned database that contains risk-related information and risk assessment throughout the life cycle of a project. The tool is tested on a real construction project. The case study findings demonstrate that it can be used for storing as well as updating risk-related information and finally, carrying out a post-project appraisal. The major weaknesses of the tool are identified as, subjectivity of the risk rating process and unwillingness of people to enter information about reasons of failure.     

地下室中央特大型钢梁柱安装施工技术

针对在地下室中央按常规工序安装特大型钢梁柱构件存在的施工问题,结合具体工程提出一种新颖的技术解决思路,即设置后浇带,划分主裙楼地下室分阶段先后施工顺序,利用临近裙楼未开挖场地作为起重机吊装作业平台,通过接高平台底工程桩以满足起重机基础承载要求。并根据工艺流程,着重对地下室分阶段界面划分、起重机吊装平台设计以及钢构件安装进行介绍。经过多项类似工程的成功实施,证明该技术具有安全、质量保证、工期缩短、费用节省等诸多优点。     

天津第一部现代城市规划--《天津特别市物质建设方案》

《天津特别市物质建设方案》由梁思成和张锐在1930年完成,它是天津历史上第一份具有现代意义的城市规划文件。这份规划不仅指导了当时天津的城市建设,而且向社会宣传和推广了现代城市的观念,在近代天津历史上具有重要的地位。本文对《天津特别市物质建设方案》的招标过程进行了挖掘整理,并结合当时的时代背景和社会环境对其规划内容进行了分析研究。     

基于改进网络分析法（ANP）的工程交易模式选择研究

工程交易模式,不仅定义了工程项目参与各方的角色和责任,同时也为项目的设计、采购、建设提供了框架。选择适当的工程交易模式是业主进行工程项目决策的关键问题。网络分析法（ANP）是层次分析法（AHP）的延伸,不仅考虑了综合因素,同时考虑了各因素之间的相互影响关系。在已有的研究基础上统计出影响工程交易模式选择的主要因素,建立了多层次的ANP 模型,并将三角模糊数引入到模型的求解过程,增加了评估的准确性,为业主进行工程交易模式的选择提供了一种有效的方法。