Increasing the use of social sustainability in the decision-making process for build-ing and infrastructure projects requires that it be defined such that it can be evaluated objectively.One potential indicator of soc...Increasing the use of social sustainability in the decision-making process for build-ing and infrastructure projects requires that it be defined such that it can be evaluated objectively.One potential indicator of social sustainability in infrastruc-ture projects is public opinion,which can provide a means to evaluate the level of social sustainability on a project based on personal values.Public opinion includes both support and opposition for a project.In this study,the causes or triggers for public opposition to a construction project are identified and then compared to principles of social sustainability to determine if they are related.Eight case study projects were used to identify common triggers of public opposition.The results suggest that common triggers of public opposition are related to land acquisition,escalating construction costs and the presence of endangered species on the project site.Eight of the twelve principles of social sustainability that were identified were determined to be related to public opposition.The results of this study suggest that public opposition could be used as a measure for some elements of social sus-tainability but that further research into other measures for social sustainability is necessary.展开更多
Concession period is a key factor in the arrangement of a build-operate-transfer(BOT) contract. This paper proposes a stochastic concession period model for infrastructure projects under a BOT scheme, which takes into...Concession period is a key factor in the arrangement of a build-operate-transfer(BOT) contract. This paper proposes a stochastic concession period model for infrastructure projects under a BOT scheme, which takes into account the impact of risks and the risk attitudes of the private investor and the government. A hypothetical case is simulated by using the Monte Carlo simulation method to illustrate the proposed model. The results indicate that even for a project with the same estimations, the concession interval can be different and depends a lot on the risk attitudes of the private investor and the government. The proposed model provides a more reasonable concession interval based on which a specific concession period can be obtained through negotiation between the two parties.展开更多
Financial incentives that stimulate energy investments under public-private partnerships are considered scarce public resources,which require deliberate allocation to the most economically justified projects to maximi...Financial incentives that stimulate energy investments under public-private partnerships are considered scarce public resources,which require deliberate allocation to the most economically justified projects to maximize the social benefits.This study aims to solve the financial incentive allocation problem through a real option-based nonlinear integer programming approach.Real option theory is leveraged to determine the optimal timing and the corresponding option value of providing financial incentives.The ambiguity in the evolution of social benefits,the decision-maker’s attitude toward ambiguity,and the uncertainty in social benefits and incentive costs are all considered.Incentives are offered to the project portfolio that generates the maximum total option value.The project portfolio selection is formulated as a stochastic knapsack problem with random option values in the objective flinction and random incentive costs in the probabilistic budget constraint.The linear probabilistic budget constraint is subsequently transformed into a nonlinear deterministic one.Finally,the integer non-linear programming problem is solved,and the optimality gap is computed to assess the quality of the optimal solution.A case study is presented to illustrate how the limited financial incentives can be optimally allocated under uncertainty and ambiguity,which demonstrates the efficacy of the proposed method.展开更多
No Projects Coopera- Total Invest- Investment Chinese Partners tion Mode ment Predicted Proportion KF3-01 Sewage Treatment Plant J.V. US$30 million Chinese 30% Beijing Economic with land as & Technological investm...No Projects Coopera- Total Invest- Investment Chinese Partners tion Mode ment Predicted Proportion KF3-01 Sewage Treatment Plant J.V. US$30 million Chinese 30% Beijing Economic with land as & Technological investment, 70% Development Zone for foreign partner SZ3-02 Beijing freight transport J.V. US$85 million Through Beijing Traffic Bureau hub of southwest highway negotiation SZ3-03 Beijing southeast international J.V. US$40 million 50% for each ditto container展开更多
Sondu-Miriu hydropower （SMHP） project experienced delay for about five years and one of the contributing factors was delayed payment of the contractor, with ripples effect extending down the contractual hierarchy. T...Sondu-Miriu hydropower （SMHP） project experienced delay for about five years and one of the contributing factors was delayed payment of the contractor, with ripples effect extending down the contractual hierarchy. This study assessed the effects of delayed payment of the contractor on the completion of SMHP project in Kisumu County, Kenya. More specifically, the study addressed two research questions： What is the relative importance of delayed payment of the contractor compared to other forms of contractual delays？ What is the perceived effect of delayed payment of the contractor on the project＇s completion？ A causal-comparative design was adopted and primary data sourced in May 2011 from 39 senior management staff of contractual parties. Relative importance index （RII） was used to determine the relative importance of perceived effects of delayed payment of the contractor on the project＇s completion; while Kendell＇s coefficient of concordance was applied to determine the degree of agreement among participants regarding their perceived effects of delayed payment. The study found that delayed payment of the contractor affected the project by causing： loss of productivity and efficiency （71.8%）; increase in time-related costs （71.8%）; re-scheduling and re-sequencing of works （69.2%）; extension of time and acceleration （69.2%）; as well as prevention of early completion （53.8%）. The study concludes that timely payment of contractors is crucial for ensuring the continuity of works and completion of infrastructural projects within time, budget, and quality specifications. The study recommends the need for appropriate mitigative measures against potential risks, such as delayed disbursement of funds by external financiers, delayed approval of contractors＇ payment requests, as well as community participation and involvement of civil society to influence accountability in the management of project funds and expedite disbursement of funds for subsequent project phases.展开更多
A number of studies conducted in Kenya </span><span style="font-family:Verdana;">and </span><span style="font-family:Verdana;">internationally indicate</span>...A number of studies conducted in Kenya </span><span style="font-family:Verdana;">and </span><span style="font-family:Verdana;">internationally indicate</span><span style="font-family:Verdana;">d</span><span style="font-family:""><span style="font-family:Verdana;"> that most of the construction firms and contractors do not seem to strictly observe safety administration in construction industry, hence compromised performance at implementation stage of projects and even later in the post implementation or post-delivery stage. The study aimed to examine the influence of contractors’ safety record on road performance. This is to create better understanding of how the safety record of contractors could either positively or negatively influence performance of roads during post-delivery stage. The study used both descriptive survey research design and correlation design based on a pragmatic mixed method approach. Through stratified sampling and proportionate sampling, a sample of 210 was drawn from a population of 460 comprising of registered contractors and Public Service Vehicles (PSV) drivers within Nairobi County in Kenya. Questionnaires were distributed using simple random sampling. The questionnaires returned were 153 in total representing 72.8% of all questionnaires distributed to the respondents. Data was descriptively analyzed using percentages, frequencies, means and standard deviations for measuring central tendency and variability. Inferential analysis was done by use of correlation and regression. The descriptive analysis revealed that safety policy management system, insurance policy, and adequacy of standards in addressing safety outcome are to some extent practiced and adhered to. However, compliance behavior to safety procedures is still weak and requires improvement. The null hypothesis was tested and the results obtained from a simple linear regression indicated that, R = 0.657, R</span><sup><span style="font-size:12px;font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> = 0.431, B = 0.359, t = 10.703, F (1,151) = 114.558, p = 0.000 < 0.05. This means that contractors’ safety record has a strong positive and significant relationship with road performance and that 43.1% of variation in performance is explained by safety record. This study recommends that contractors’ safety record should be part</span></span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> and parcel of the evaluation criteria used in selection of a suitable road contractor to ensure road performance is achieved even after construction is completed. The study is significant in that it contributes to the body of knowledge by providing empirical data on the need for safety procedures in urban road construction and beyond.展开更多
This article proposes the use of current European standards and verification rules for EPDs （environmental product declarations） as a basis for evaluating the climate impact of contractors＇ alternative designs of i...This article proposes the use of current European standards and verification rules for EPDs （environmental product declarations） as a basis for evaluating the climate impact of contractors＇ alternative designs of infrastructural projects. The proposed conceptual framework for verified climate calculations is based on the Swedish-based, the International EPD System. Several Swedish and Norwegian stakeholders were engaged in this joint project to understand driving forces and obstacles and provide key insights for the successful implementation of the framework for a transparent and comparable assessment of climate impact from alternative design options. In order to perform a sharp test of some main hypothesizes, the project participants tested the proposed framework in bridge and roads projects.展开更多
文摘Increasing the use of social sustainability in the decision-making process for build-ing and infrastructure projects requires that it be defined such that it can be evaluated objectively.One potential indicator of social sustainability in infrastruc-ture projects is public opinion,which can provide a means to evaluate the level of social sustainability on a project based on personal values.Public opinion includes both support and opposition for a project.In this study,the causes or triggers for public opposition to a construction project are identified and then compared to principles of social sustainability to determine if they are related.Eight case study projects were used to identify common triggers of public opposition.The results suggest that common triggers of public opposition are related to land acquisition,escalating construction costs and the presence of endangered species on the project site.Eight of the twelve principles of social sustainability that were identified were determined to be related to public opposition.The results of this study suggest that public opposition could be used as a measure for some elements of social sus-tainability but that further research into other measures for social sustainability is necessary.
基金the Research Project Ministry of Housing and Urban-Rural Development of PRC(No.2011-123-22)Fund of China International Contractors Association
文摘Concession period is a key factor in the arrangement of a build-operate-transfer(BOT) contract. This paper proposes a stochastic concession period model for infrastructure projects under a BOT scheme, which takes into account the impact of risks and the risk attitudes of the private investor and the government. A hypothetical case is simulated by using the Monte Carlo simulation method to illustrate the proposed model. The results indicate that even for a project with the same estimations, the concession interval can be different and depends a lot on the risk attitudes of the private investor and the government. The proposed model provides a more reasonable concession interval based on which a specific concession period can be obtained through negotiation between the two parties.
文摘Financial incentives that stimulate energy investments under public-private partnerships are considered scarce public resources,which require deliberate allocation to the most economically justified projects to maximize the social benefits.This study aims to solve the financial incentive allocation problem through a real option-based nonlinear integer programming approach.Real option theory is leveraged to determine the optimal timing and the corresponding option value of providing financial incentives.The ambiguity in the evolution of social benefits,the decision-maker’s attitude toward ambiguity,and the uncertainty in social benefits and incentive costs are all considered.Incentives are offered to the project portfolio that generates the maximum total option value.The project portfolio selection is formulated as a stochastic knapsack problem with random option values in the objective flinction and random incentive costs in the probabilistic budget constraint.The linear probabilistic budget constraint is subsequently transformed into a nonlinear deterministic one.Finally,the integer non-linear programming problem is solved,and the optimality gap is computed to assess the quality of the optimal solution.A case study is presented to illustrate how the limited financial incentives can be optimally allocated under uncertainty and ambiguity,which demonstrates the efficacy of the proposed method.
文摘No Projects Coopera- Total Invest- Investment Chinese Partners tion Mode ment Predicted Proportion KF3-01 Sewage Treatment Plant J.V. US$30 million Chinese 30% Beijing Economic with land as & Technological investment, 70% Development Zone for foreign partner SZ3-02 Beijing freight transport J.V. US$85 million Through Beijing Traffic Bureau hub of southwest highway negotiation SZ3-03 Beijing southeast international J.V. US$40 million 50% for each ditto container
文摘Sondu-Miriu hydropower （SMHP） project experienced delay for about five years and one of the contributing factors was delayed payment of the contractor, with ripples effect extending down the contractual hierarchy. This study assessed the effects of delayed payment of the contractor on the completion of SMHP project in Kisumu County, Kenya. More specifically, the study addressed two research questions： What is the relative importance of delayed payment of the contractor compared to other forms of contractual delays？ What is the perceived effect of delayed payment of the contractor on the project＇s completion？ A causal-comparative design was adopted and primary data sourced in May 2011 from 39 senior management staff of contractual parties. Relative importance index （RII） was used to determine the relative importance of perceived effects of delayed payment of the contractor on the project＇s completion; while Kendell＇s coefficient of concordance was applied to determine the degree of agreement among participants regarding their perceived effects of delayed payment. The study found that delayed payment of the contractor affected the project by causing： loss of productivity and efficiency （71.8%）; increase in time-related costs （71.8%）; re-scheduling and re-sequencing of works （69.2%）; extension of time and acceleration （69.2%）; as well as prevention of early completion （53.8%）. The study concludes that timely payment of contractors is crucial for ensuring the continuity of works and completion of infrastructural projects within time, budget, and quality specifications. The study recommends the need for appropriate mitigative measures against potential risks, such as delayed disbursement of funds by external financiers, delayed approval of contractors＇ payment requests, as well as community participation and involvement of civil society to influence accountability in the management of project funds and expedite disbursement of funds for subsequent project phases.
文摘A number of studies conducted in Kenya </span><span style="font-family:Verdana;">and </span><span style="font-family:Verdana;">internationally indicate</span><span style="font-family:Verdana;">d</span><span style="font-family:""><span style="font-family:Verdana;"> that most of the construction firms and contractors do not seem to strictly observe safety administration in construction industry, hence compromised performance at implementation stage of projects and even later in the post implementation or post-delivery stage. The study aimed to examine the influence of contractors’ safety record on road performance. This is to create better understanding of how the safety record of contractors could either positively or negatively influence performance of roads during post-delivery stage. The study used both descriptive survey research design and correlation design based on a pragmatic mixed method approach. Through stratified sampling and proportionate sampling, a sample of 210 was drawn from a population of 460 comprising of registered contractors and Public Service Vehicles (PSV) drivers within Nairobi County in Kenya. Questionnaires were distributed using simple random sampling. The questionnaires returned were 153 in total representing 72.8% of all questionnaires distributed to the respondents. Data was descriptively analyzed using percentages, frequencies, means and standard deviations for measuring central tendency and variability. Inferential analysis was done by use of correlation and regression. The descriptive analysis revealed that safety policy management system, insurance policy, and adequacy of standards in addressing safety outcome are to some extent practiced and adhered to. However, compliance behavior to safety procedures is still weak and requires improvement. The null hypothesis was tested and the results obtained from a simple linear regression indicated that, R = 0.657, R</span><sup><span style="font-size:12px;font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> = 0.431, B = 0.359, t = 10.703, F (1,151) = 114.558, p = 0.000 < 0.05. This means that contractors’ safety record has a strong positive and significant relationship with road performance and that 43.1% of variation in performance is explained by safety record. This study recommends that contractors’ safety record should be part</span></span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> and parcel of the evaluation criteria used in selection of a suitable road contractor to ensure road performance is achieved even after construction is completed. The study is significant in that it contributes to the body of knowledge by providing empirical data on the need for safety procedures in urban road construction and beyond.
文摘This article proposes the use of current European standards and verification rules for EPDs （environmental product declarations） as a basis for evaluating the climate impact of contractors＇ alternative designs of infrastructural projects. The proposed conceptual framework for verified climate calculations is based on the Swedish-based, the International EPD System. Several Swedish and Norwegian stakeholders were engaged in this joint project to understand driving forces and obstacles and provide key insights for the successful implementation of the framework for a transparent and comparable assessment of climate impact from alternative design options. In order to perform a sharp test of some main hypothesizes, the project participants tested the proposed framework in bridge and roads projects.
