Xin Wang, Shaoze Luo and Qiang Yuan
A new roller compacted concrete dam of Fengman hydropower station was determined to be built in the toe of the old dam which had been identified as a dangerous dam. The new dam…
Abstract
Purpose
A new roller compacted concrete dam of Fengman hydropower station was determined to be built in the toe of the old dam which had been identified as a dangerous dam. The new dam during construction would be impacted by the high‐speed flow discharged from the old dam. This is an important problem met for the first time in China, which would affect the whole project construction. The purpose of this paper is to describe a series of erosion experiments of the new dam material.
Design/methodology/approach
A kind of high‐speed flow erosion test apparatus was developed for erosion experiment of the new dam material. The maximum jet velocity was up to 40 m/s and the section area of the nozzle was 25 cm2. In the process of experiments, the equipment showed its good performance. Erosive wear tests of two types of materials used in the new dam, a roller compacted concrete and a distorted concrete with four kinds of ages were carried out with the flow velocity in the range of 30‐35 m/s.
Findings
Erosion parameters and erosion laws of the two types of concretes with different ages were obtained, and a general relationship had been found between erosion rate and flow velocity: with velocity exponent between 3.33 and 3.93. It was also concluded that the erosion resistance of the distorted concrete was better than that of the roller compacted concrete and the mechanics properties of the concretes of over 14 days age was influenced slightly by water impacted.
Originality/value
The test results would play a practical technique guide role for the safety of this project during construction in the flood season.
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Dedong Wang, Shaoze Fang and Kaili Li
The purpose of this paper is to study the mechanisms governing dynamic changes in relational and contractual governance at different stages of government-funded mega construction…
Abstract
Purpose
The purpose of this paper is to study the mechanisms governing dynamic changes in relational and contractual governance at different stages of government-funded mega construction projects (MCPs) by studying their different effects on project performance and participants’ opportunism.
Design/methodology/approach
Partial least squares structural equation modeling was used to test eight hypotheses based on data collected from 147 respondents in different participating organizations in Chinese MCPs.
Findings
First, contractual governance has a stronger positive impact on project performance than relational governance in the early stage of MCPs, while relational governance exerts more positive effects on project performance than contractual governance in the middle and late stages. Second, opportunism is a mediator variable between governance mechanisms and project performance, and relational governance is more effective than contractual governance in restricting opportunism.
Originality/value
In contrast to a static analysis of project governance mechanisms, this study examines dynamic changes in the governance mechanisms of MCPs in the Chinese context by considering the mediating role of opportunism as well as guanxi as an element of relational governance, thus filling in gaps in the literature on MCP governance and contributing to the development of MCP management theory.
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Dedong Wang, Hongwei Fu and Shaoze Fang
The low success rate of megaprojects stems from the opportunism triggered by uncertainty. Developing trust between participants is an effective means to reduce uncertainty, but…
Abstract
Purpose
The low success rate of megaprojects stems from the opportunism triggered by uncertainty. Developing trust between participants is an effective means to reduce uncertainty, but this process is inevitably affected by contracts. The purpose of this paper is to examine the impact of uncertainty on participants’ opportunism in megaprojects and the effect of trust on reducing uncertainty. At the same time, the moderating effects of contractual control are tested.
Design/methodology/approach
This research classifies trust into competence-based trust and goodwill-based trust and categorizes uncertainty into environmental uncertainty and behavioral uncertainty. Partial least squares structural equation modeling is used to test the hypotheses based on data collected from 172 respondents.
Findings
The results show a positive correlation between the two types of uncertainty and opportunism. For the governance of uncertainty, competence-based trust can reduce environmental uncertainty, but it is ineffective for behavioral uncertainty, and goodwill-based trust has a significant effect on both types of uncertainty. The test of moderating effects shows that contractual control strengthens the effect of competence-based trust but weakens the effect of goodwill-based trust, which means that contractual control complements competence-based trust and substitutes for goodwill-based trust.
Research limitations/implications
This research enriches the theory of megaproject management. First, it validates the role of competence-based trust and goodwill-based trust in reducing the different types of uncertainty in megaprojects. Second, this study clarifies the substitution or complementarity between contractual control and different dimensions of trust in the context of high uncertainty, which provides a comprehensive answer to prior research inconsistencies on contractual control and trust.
Practical implications
For practice, this research provides some implications for megaproject management. First, project managers should recognize that the match between trust and project uncertainty is key to the success of megaproject governance. For example, some megaprojects involve many organizations, and there are many difficulties in behavioral supervision and performance appraisal. Therefore, developing goodwill-based trust between participants through positive interactions is an effective means to reduce the behavioral uncertainty of all participants and to curb opportunistic behaviors.
Originality/value
This research validated the role of competence-based trust and goodwill-based trust in reducing the different types of uncertainty in megaprojects. Furthermore, it clarifies the substitution or complementarity between contractual control and different dimensions of trust in the context of high uncertainty, which provides a comprehensive answer to prior research inconsistencies on contractual control and trust.
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Abstract
Purpose
By reducing the coating thickness of the weak scattering source, the coating weight of the absorbing material can be reduced by 35% with little effect on the RCS.
Design/methodology/approach
To alleviate the weight-increasing problem caused by a large number of coating of absorbing materials, a method for zonal coating of absorbing materials for a stealth helicopter was proposed. By appropriately reducing the thickness of the coating at the secondary scattering locations, the amount of coating used is significantly reduced.
Findings
Compared with the full-coated, the zonal coating scheme achieves the corresponding RCS reduction effect.
Practical implications
Zonal coating design can achieve the effect of reducing coating weight and cost.
Originality/value
The effects of different coating methods on RCS were verified by electromagnetic scattering simulation, and the applicability of the zonal coating design of the absorbing material to the stealth helicopter was verified.
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This study identifies three main CSR motivations (i.e. strategic benefits, altruism and greenwashing) and explores the relationship between CSR motivations and environmental…
Abstract
Purpose
This study identifies three main CSR motivations (i.e. strategic benefits, altruism and greenwashing) and explores the relationship between CSR motivations and environmental collaboration by considering the mediating role of environmental commitment and the moderating role of team autonomy.
Design/methodology/approach
The data collected from 336 respondents in the construction industry, structural equation modeling and bootstrapping were used to test hypotheses.
Findings
The findings show that altruistic CSR enhances environmental collaboration through enhancing environmental commitment, whereas greenwashing CSR damages environmental collaboration through reducing environmental commitment. Although there is no direct association between strategic CSR and environmental collaboration, environmental commitment mediates the effects of strategic CSR on environmental collaboration. Moreover, the positive effect of strategic CSR and altruistic CSR on environment commitment is stronger when team autonomy is stronger, whereas the negative effect of greenwashing CSR on environment commitment is weaker when team autonomy is stronger.
Originality/value
The findings contribute to the understanding of how CSR motivations can act as catalysts for collaborative efforts in addressing environmental issues within construction projects and offer theoretical understanding of team autonomy by illustrating its role in shaping organizational responses to CSR motivations. The findings can provide insights into why and how participating teams can collaborate better on environmental management, enriching the knowledge of environmental management practices in construction projects.