Infrastructure Engineering - Research Publications
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ItemOptimized Design of Piled Embankment Using a Multi-Effect Coupling Model on a Coastal Highway(MDPI, 2022-09-01)This study presents a multi-effect coupling model to optimize the design of a geosynthetic-reinforced pile-supported embankment (GRPSE) considering the coupling effects of soil arching, membranes, and pile–soil interaction on a coastal highway. The developed model could optimize the design of the GRPSE to fulfill the design and construction requirements at a relatively low project cost. This was achieved by adjusting the critical factors that govern the settlement of GRPSEs, such as pile spacing, tensile stiffness of geosynthetic reinforcement (GR), arrangement of piles, pile cap size, and cushion thickness. The model predictions were validated by a series of field tests using a range of geotechnical sensors. The results show that model predictions agreed with experimental measurements reasonably well. In addition, the results indicate that in comparison to a square arrangement of piles, a triangle net arrangement can decrease the differential settlement of pile soil. Furthermore, this study demonstrates that a change in the GR’s tensile stiffness has little impact on the settlement of GRPSEs. This study can help to improve the stability of roadbeds of coastal highways.
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ItemPercolation Threshold of Red-Bed Soft Rock during Damage and Destruction(MDPI, 2022-08-01)The critical damage point of the red-bed soft rock percolation phenomenon can be described as the percolation threshold. At present, there are insufficient theoretical and experimental studies on the percolation phenomenon and threshold of red-bed soft rock. In combination with theoretical analysis, compression experiment and numerical simulation, the percolation threshold and destruction of red-bed soft rock are studied in this paper. The theoretical percolation threshold of red-bed soft rock was obtained by constructing a renormalization group model of soft rock. Based on damage mechanics theory, rock damage characterization and strain equivalent hypothesis, a constitutive model of red-bed soft rock percolation damage was obtained. The percolation threshold of red-bed soft rock was determined by compression test and a damage constitutive model, which verified the rationality of the theoretical percolation threshold, and we numerically simulated the percolation of red-bed soft rock under triaxial compression. The results showed that the percolation threshold increases as the confining pressure rises, but decreases significantly with the action of water. In this study, the critical failure conditions and percolation characteristics of red-bed soft rock under different conditions were obtained. The relationship between percolation and soft rock failure was revealed, providing a new direction for studying the unstable failure of red-bed soft rock.
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ItemAnalytical Framework for Understanding the Differences between Technical Standards Originating from Various Regions to Improve International Hydropower Project Delivery(MDPI, 2022-02-01)The international hydropower construction market is continuously growing during the past decade. The existing literature points out that contractors are facing ongoing difficulties in achieving the objectives of developing international hydropower projects, which largely arise from the misunderstanding and poor use of international technical standards. However, there is a lack of a coherent framework to help systematically analyze the differences between technical standards originating from various regions. This study establishes an analytical framework that incorporates the essential factors of technical standards, namely philosophy of standards, logical structure, completeness of standards, calculation method, equipment and material requirements, test method, construction method, and application conditions of standards, and demonstrates their relationships from a holistic perspective. With support of the data collected from Chinese contractors, the results revealed the application status of various technical standards and their differences. Hierarchical cluster analysis demonstrates that unfamiliarity with the differences between domestic and international technical standards can cause multiple problems in international hydropower project delivery, concerning applying international standards, integrated project management, design, procurement, and construction, which have broad theoretical and practical implications. The outcomes of this study can not only help contractors improve their capabilities of applying international standards for achieving superior international hydropower project performance, but also facilitate mutual recognition of the standards from various regions, thereby maximizing the effectiveness of global resources such as expertise, technologies, methods, and products.
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ItemIndentation into an aluminium panel by the impact of a rigid spherical object(Elsevier BV, 2022-11)This paper introduces algebraic expressions for determining the amount of permanent indentation caused to an aluminium panel when impacted by a rigid spherical object. The magnitude of indentation is observed to vary significantly with the position of impact within the panel when the impactor and the velocity of impact are kept the same. This spatial variation of indentation is caused by the changes in the combinational mass (which is in turn function of the participating mass of the plate) and the Coefficient of Restitution COR. Both parameters are shown to correlate with the position of impact. The proposed algebraic expression featuring the combinational mass and COR as input parameters, allows potential damage to the panel to be predicted conveniently in day-to-day engineering practices. The original contribution of this article is in illustrating this phenomenon analytically, and have the analytical predictions verified by impact experimentation which has been conducted by the authors on panels of varying dimensions.
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ItemNo Preview AvailableThe synthesis of soft rocks based on physical and mechanical properties of red mudstone(PERGAMON-ELSEVIER SCIENCE LTD, 2022-03-01)
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ItemNo Preview AvailableApplication of New Polymer Composite Materials in Rock Slope Ecological(IOP Publishing, 2021-10-27)
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ItemEarly Risk Warning of Highway Soft Rock Slope Group Using Fuzzy-Based Machine Learning(MDPI, 2022-03-01)Maintaining the stability of highway soft rock slopes is of critical importance for ensuring the safety of road networks. Although much research has been carried out to assess the stability of individual soft rock slope, the goal of efficient and effective risk management focusing on multiple highway soft rock slopes has not been fully achieved due to the many complex factors involved and the interactions among these factors. In the present study, a machine learning algorithm based on a fuzzy neural network (FNN) and a comprehensive evaluation method based on the FNN is developed, in order to identify and issue early warnings regarding the risks induced by soft rock slopes along highways, in an efficient and effective way. Using a large amount of collected soft rock slope information as training and validation data, an FNN-based risk identification model is first developed to identify the risk level of individual soft rock slope based on the meteorological conditions, topographical and geomorphological factors, geotechnical properties, and the measured horizontal displacement. An FNN-based comprehensive evaluation method is then developed, in order to quantify the risk level of a soft rock slope group according to the slope, road and external factors. The results show that the risk level identification accuracy obtained based on validation of the FNN model was higher than 90%, and the model showed a good training effect. On this basis, we further made early warnings of the risks of soft rock slope groups. The proposed early-warning model can quickly and accurately evaluate the risk posed by multiple soft rock slopes to a highway, thereby ensuring the safety of the highway.
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ItemEvaluating uncertainties to deliver enhanced service performance in education PPPs: a hierarchical reliability framework(EMERALD GROUP PUBLISHING LTD, 2022-06-20)Purpose This study aims to develop a hierarchical reliability framework to evaluate the service delivery performance of education public–private partnerships (PPPs) effectively and efficiently during long-term operations. Design/methodology/approach The research design included development and test phases. In the development phase, three performance layers, i.e. indicator, component and system, in the education service delivery system were identified. Then, service component reliability was computed through first order reliability method (FORM). Finally, the reliability of the service system was obtained using dynamic component weightings. A PPP school example in Australia was set up in the test phase, where performance indicators were collected from relevant contract documents and performance data were simulated under three assumptive scenarios. Findings The example in the test phase yielded good results for the developed framework in evaluating uncertainties of service delivery performance for education PPPs. Potentially underperforming services from the component to the system level at dynamic timepoints were identified, and effective preventative maintenance strategies were developed. Research limitations/implications This research enriches reliability theory and performance evaluation research on education PPPs. First, a series of performance evaluation indicators are constructed for assessing the performance of the service delivery of the education PPP operations. Then, a reliability-based framework for service components and system is developed to predict service performance of the PPP school operations with consideration of a range of uncertainties during project delivery. Practical implications The developed framework was illustrated with a real-world case study. It demonstrates that the developed reliability-based framework could potentially provide the practitioners of the public sector with a basis for developing effective preventative maintenance strategies with the aim of prolonging the service life of the PPP schools. Originality/value Evaluating education PPPs is challenging as it involves long-term measurement of various service components under uncertainty. The developed reliability-based framework is a valuable tool to ensure that reliability is maintained throughout the service life of education PPPs in the presence of uncertainty.