Structural equation model of project planning effectiveness

Previous research studies investigating the impact of situational variables on project planning effectiveness have not examined how the situational variables work together to influence planning effectiveness. A structural equation model (SEM) has been developed for describing and quantifying the influence of situational factors in project environments and organizational characteristics of performing organizations on project planning effectiveness. The individual effects of directly‐observable variables on the project planning process were evaluated using regression analysis. The SEM approach enables the modelling of multiple factors as latent not‐directly‐measurable variable sets, thus providing a theoretical insight into how individual influence factors work together to determine the effectiveness of project planning efforts. The project environment has a dominant significant influence on the potential effectiveness of project planning efforts. In contrast, the influence of organizational characteristics is relatively insignificant.     

Prediction of potential damage due to severe earthquakes

A statistical model is developed to estimate the seismic vulnerability of low- to mid-rise reinforced concrete buildings. The model is based on a novel utilization of the discriminant analysis technique of multivariate statistics. Number of stories above the ground level (N), soft story index (SSI), overhang ratio (OHR), minimum normalized lateral stiffness index (MNLSTFI), minimum normalized lateral strength index (MNLSI) and normalized redundancy score (NRS) are selected as the basic estimation variables. The earthquake damage data compiled for the 12 November 1999 Duzce earthquake are used to develop a discriminant function in terms of these estimation variables. The discriminant score obtained from the resulting discriminant function is then used to estimate the damage state of buildings ranging from no damage to collapse, with intermediate damage states of light, moderate and severe. Correct classification rates ranging between 62% and 95% obtained for the seismic damage data associated with the recent earthquakes that occurred in Turkey support the predictive ability of the proposed model.     

Estimation of project total cost and duration for housing projects in the U.K.

There are a number of variables which act individually and in combination to influence project total cost and duration. The extent of the effect of these variables is dependent on the nature of the project. A project is defined in terms of its constituent variables. This paper is concerned with a variety of project definitions within the category of housing projects in the U.K. The most influential variables are examined and, in quantified terms, the extent of the relationship between these variables and project total cost and duration is determined. To this end, two separate models are developed and proposed for the estimation of project cost and duration. While the model for the latter encompasses the former as a variable, the model for the estimation of project cost is independent from project duration.     

A catastrophe model of construction conflict behavior

Buildings are part of the built environment in which many activities are performed. One of the critical part of a development process is the physical construction of the proposed facility. As such an efficient construction process is invaluable. Moreover, due to the inherent divergence in interest, conflict among the contracting parties appears inevitable. Escalating conflict level may turn into psychological struggles between the contracting parties and manifests as dispute. The unfortunate outcomes are loss of productivity and increase in cost of construction. This paper describes the dynamic change in construction conflict behavior based on the catastrophe theory. How conflict behavior is affected by conflict level is first discussed. As such a catastrophe model of construction conflict behavior with tension level, behavioral flexibility as control variables is proposed. It is suggested that conflict is positively correlated to the tension level among the project team and subject to the moderating effect of the behavioral flexibility displayed by the project team members. The model suggests a sudden jump in conflict level will occur when tension reaches a threshold. Once this happens the conflict level will not subside even the tension level returns to the threshold just reached. The proposed model was tested by an empirical study that affirms: (1) The appropriateness of the use of tension and behavioral flexibility as control variables; (2) catastrophe model is a better fit to describe construction conflict behavior than the linear and logistic model; and (3) the bimodal nature of construction conflict behavior. The model reinforces the conventional wisdom of ‘prevention is better than cure’ as far as construction conflict resolution is concerned.     

隧洞围岩稳定性评价的Bayes判别分析法及应用

提出了隧洞围岩稳定性评价的Bayes判别分析法.通过介绍Bayes判别分析法的理论,并考虑影响隧洞围岩稳定性的因素,建立具体的Bayes判别分析模型进行判别.以隧道工程中的大量实测资料作为学习样本进行训练,并利用回代确认估计法对训练后的模型进行检验,最后将该模型对隧洞的围岩情况进行预测.研究结果表明,经过训练后的Bayes判别分析模型误判率很低,判别准确率很高,可以在实际工程中应用.     

Application of chemometrics in river water classification

The main aim of this work is focused on water quality classification of the Brda river (Poland) and evaluation of pollution data obtained by the monitoring measurement during the period 1994-2002. The study presents the application of selected chemometric techniques to the pollution monitoring dataset, namely, cluster analysis, principal component analysis, discriminant analysis and factor analysis. The obtained results allowed to determine natural clusters and groups of monitoring locations with similar pollution character and identify important discriminant variables. Chemometric analysis confirmed the classification of water purity of the Brda river made by the Inspection of Environmental Protection but the results showed more differentiation between monitored locations. This enables better evaluation of the water quality in a monitored region. On the basis of the chemometric approach, it was also found that some locations were under the high influence of municipal contamination, and some others under the influence of agriculture (discharges from fields) within the observed time period.     

隐性交易成本对承包商工程争端解决决策影响分析

工程争端不可避免,随着第三方的介入,解决争端的成本花费也随之递增。通过文献分析及专家访谈,识别出11项构成工程争端隐性成本的影响因素,对每一项因素导致成本增加的影响方式进行了详细分析。通过因子分析,获得5类工程争端隐性成本:商务关系成本、时间成本、咨询成本、信用成本以及司法腐败成本,且重要性依次降低。研究结果有助于承包商认识到隐性成本对争端处理决策的影响,理性地设置谈判底线,避免争端升级,实现双赢。     

Modeling construction time in Spanish building projects

The literature states that project duration is affected by various scope factors. Using 168 building projects carried out in Spain, this paper uses the multiple regression analysis to develop a forecast model that allows estimating project duration of new builds. The proposed model uses project type, gross floor area (GFA), the cost/GFA relationship and number of floors as predictor variables. The research identified the logarithmic form of construction speed as the most appropriate response variable. GFA has greater influence than cost on project duration but both factors are necessary to achieve a forecast model with the highest accuracy. We developed an analysis to verify the stability of forecasted values and showed how a model with high values of fit and accuracy may display an anomalous behavior in the forecasted values. The sensitivity of the proposed forecast model was also analyzed versus the variability of construction costs.     

西安地区单桩荷载传递双曲线模型与工程应用

选用双曲线荷载传递函数分析单桩的荷载传递规律。通过分析各参数对传递函数的影响,认为桩土间的极限位移是双曲线传递函数的主要参数。然后以西安地区的26个工程钻孔灌注桩的现场试桩资料为基础,利用Matlab提供的优化工具箱对荷载传递函数中的参数进行了优化,得到各工程中的传递函数的参数,同时发现桩土间极限位移离散程度在各参数中最大,这与理论分析相一致。最后与工程实例进行了对比验证,结果表明,把利用该优化方法得到的双曲线荷载传递函数的参数作为西安地区的经验参数是可靠的。     

一种公路隧道围岩判别预测的新方法

基于距离判别分析理论,结合大量高速公路隧道围岩的工程数据,建立了公路隧道围岩预测的判别模型,工程应用表明,该模型结果与实际情况吻合良好,说明了该模型在公路隧道预测中具有良好的实用性和有效性.     

基于Fisher模型的TBM隧道围岩分类研究

根据TBM掘进过程中得到的大量实测参数,建立相应的费希尔判别函数来对围岩状况进行反推,考虑刀盘转速、贯入度、扭矩和推力四个因素来判断围岩质量,进而对支护管片进行选择,应用于工程实际,取得了良好效果。     

An empirical study of the benefits of construction partnering in Hong Kong

Many construction companies have adopted partnering in their construction projects over the past 10–15 years due to favourable project outcomes achieved. Its use in construction projects has been increasing rapidly as its benefits become more apparent and pervasive. This paper reviews the partnering literature within the construction field and tries to portray the comprehensive picture of benefits for the partnering practice. Through partnering and the active involvement of all key project parties, the project is more likely to be completed within budget, on time, and with the least number of conflicts, claims and work defects. Also, this paper reports upon the findings of a questionnaire survey of partnering benefits in Hong Kong. Seventy‐eight project participants completed a questionnaire to indicate the relative importance of partnering benefits. The perceived benefits were measured and ranked from the perspectives of the client, contractor and consultant for cross‐comparison. The results revealed that ‘Improved relationship amongst project participants’, ‘Improved communication amongst project participants’ and ‘More responsive to the short‐term emergency, changing project or business needs’ were the most significant benefits derived from the use of partnering. More partnering arrangements should be actively introduced into the construction procurement process so that every party can enjoy the full benefits of partnering.     

基于统计分级判别的爆破块度预测模型

依托世界多个矿山的爆破块度统计数据,以27个样本作为训练样本,10个样本作为待判样本,通过主成分分析法对原始数据加以处理,获得相对独立的新变量,后将新变量作为指标代入分类判别法中,量化爆破块度分级标准,利用多元回归分析推得不同级别相对应的块度预测模型,并与工程中广泛使用的Kuz-Rom结果进行对比。结果表明:提出的模型在建立时避免了爆破因素间的相互影响;通过对待判样本的对比预测可知,该模型预测精度优于Kuz-Rom模型,并验证了建立不同级别相对应爆破块度预测模型的正确性。     

Stratification of a cityscape using census and land use variables for inventory of building materials

A cityscape (or any landscape) can be stratified into environmental units using multiple variables of information. For the purposes of sampling building materials, census and land use variables were used to identify similar strata. In the Metropolitan Statistical Area of a cityscape, the census tract is the smallest unit for which census data are summarized and digitized boundaries are available. For purposes of this analysis, census data on total population, total number of housing units, and number of singleunit dwellings were aggregated into variables of persons per square kilometer and proportion of housing units in single-unit dwellings. The level 2 categories of the U.S. Geological Survey's land use and land cover data base were aggregated into variables of proportion of residential land with buildings, proportion of nonresidential land with buildings, and proportion of open land. The cityscape was stratified, from these variables, into environmental strata of Urban Central Business District, Urban Livelihood Industrial Commercial, Urban Multi-Family Residential, Urban Single Family Residential, Non-Urban Suburbanizing, and Non-Urban Rural.The New England region was chosen as a region with commonality of building materials, and a procedure developed for trial classification of census tracts into one of the strata. Final stratification was performed by discriminant analysis using the trial classification and prior probabilities as weights. The procedure was applied to several cities, and the results analyzed by correlation analysis from a field sample of building materials.The methodology developed for stratification of a cityscape using multiple variables has application to many other types of environmental studies, including forest inventory, hydrologic unit management, waste disposal, transportation studies, and other urban studies. Multivariate analysis techniques have recently been used for urban stratification in England.This research has been funded as part of the National Acid Precipitation Assessment Program by the National Park Service and U.S. Geological Survey.     

工程合同对承包方合作行为的影响研究:信任的中介作用

为解释以往文献关于合同对合作行为促进或抑制作用的研究分歧,以工程建设项目为背景,基于发包方视角构建了以合同控制性和协调性为自变量、承包方信任为中介、承包方角色内和角色外合作行为为因变量的理论模型,通过对340 份承包方有效问卷进行实证分析,结果表明承包方信任在合同协调性对合作行为的影响中起到部分中介作用。进一步得出发包方应充分认识到合同的控制和协调功能,重视合同协调功能用以培养和维系承包方信任;承包方信任会正向影响承包方做出相应角色内、外行为,因此发包方应该重视承包方信任的提升。     

Influence of process performance during the construction stage on achieving end‐project goals

Within a project environment, good process performance can be seen as indicative of eventual success of achieving end‐project goals. A model is proposed for identifying the links between process performance during construction and end‐project goals. The model is developed using process mapping technique to identify a number of process‐based key performance indicators (KPIs) designed for use in controlling process performance in the construction stage. These KPIs were then linked to generic project goals to measure the perceived degree of influence of process performance on the achievement of end‐project goals. The strength of these links within the model was established through a number of in‐depth interviews with respondents. Analysis of the results using methods of ranking and statistics has shown that some processes are perceived to have stronger relationships with the end‐project goals than others. The proposed process‐based KPIs hence offer an opportunity for control of the processes during the construction stage and eventually to influence the projects’ outcomes. In addition to the management of project time and cost, the model provides a broader focus of control that includes other multiple aspects such as the management of interactions between internal and external stakeholders as well as of information and quality management.     

从策划走向策动——王莽乡农业生态观光园的概念规划与实践

随着观光型农业的发展,我国大部分地区兴起了关于农业生态观光园的建设。本文以王莽乡农业生态观光园项目为例,通过对王莽乡多方有利因素的整合,结合特色发展模式及定位,在项目概念规划中制定特色鲜明的规划理念,以策划引导发展,以策划推动发展,使优势资源充分发挥并合理利用,并且在规划设计中,遵循可持续发展以及地域特征突出原则,尽可能保持原有风貌环境,最大化利用现状,从而造福当地百姓。     

Modeling Virtual Design and Construction Implementation Strategies Considering Lean Management Impacts

Virtual design and construction (VDC) implementation remains a challenge as companies lack understanding of the implementation strategies and their relation with other important improvement efforts such as lean management. This article presents a performance modeling methodology that allows companies to assess VDC implementation strategies, including lean management as a moderator. The methodology is based on a conceptual model of the implementation variables that influence project performance and a mathematical method that uses partial least squares to explain the relationships among the multiple variables. The methodology was tested using data from an existing survey to identify the variables and quantify the relationships. A significant finding is that using lean as a moderator strengthens the connection between strategies and allows a better performance on companies. The results are exploratory but provide interesting insights into VDC implementation strategies and provide evidence of the methodology's power.     

基于TSP和PCA-Bayes法的隧道围岩分级

高精度的围岩超前分级是隧道安全有效施工的重要保障。基于TSP303系统对前方围岩的预报结果,建立PCA-Bayes判别模型,选取纵波速度、横波速度、纵横波速比、泊松比、密度及静态杨氏模量作为判别指标,利用PCA法对学习样本进行降维处理,按照主成分累计方差贡献率大于85%的原则提取主成分,并将40个学习样本用提取的主成分表示。根据围岩实际揭露情况,将围岩分为II、III、IV、V 4级,各总体的先验概率以该总体的样本占比近似表示,依据平均错判损失最小的判别准则,建立各总体的Bayes判别函数,并得出各指标的得分系数,采用交互检验法评价了判别模型的优良性,根据建立的判别模型对10个待判样本进行了检验,并且与聚类分析及传统Bayes判别法的判别结果进行了对比分析。结果表明:相较于聚类分析与传统Bayes判别法,PCA-Bayes判别法的判别能力更强,准确率可达98%,提高了隧道围岩超前分级的精度。