Charles E. Via Jr. Department of Civil and Environmental Engineering
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The Charles E. Via, Jr. Department of Civil and Environmental Engineering, which is ranked in the top 10 accredited civil and environmental engineering departments by the US News and World Report survey, is one of the largest programs in the United States. The Department has 46 full-time faculty, 657 undergraduate, and 400 graduate students. Civil engineers are the principal designers, constructors, operators, and caretakers of many of the constructed facilities and systems that contribute to the high quality of life enjoyed in the United States. The Charles E. Via, Jr. Department of Civil and Environmental Engineering offers educational programs in all areas of civil engineering practice.
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Browsing Charles E. Via Jr. Department of Civil and Environmental Engineering by Department "Civil & Environmental Engineering"
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- Acoustic Emission Wave Velocity Measurement of Asphalt Mixture by Arbitrary Wave MethodLi, Jianfeng; Liu, Huifang; Wang, Wentao; Zhao, Kang; Ye, Zhoujing; Wang, Linbing (MDPI, 2021-09-13)The wave velocity of acoustic emission (AE) can reflect the properties of materials, the types of AE sources and the propagation characteristics of AE in materials. At the same time, the wave velocity of AE is also an important parameter in source location calculation by the time-difference method. In this paper, a new AE wave velocity measurement method, the arbitrary wave (AW) method, is proposed and designed to measure the AE wave velocity of an asphalt mixture. This method is compared with the pencil lead break (PLB) method and the automatic sensor test (AST) method. Through comparison and analysis, as a new wave velocity measurement method of AE, the AW method shows the following advantages: A continuous AE signal with small attenuation, no crosstalk and a fixed waveform can be obtained by the AW method, which is more advantageous to distinguish the first arrival time of the acoustic wave and calculate the wave velocity of AE more accurately; the AE signal measured by the AW method has the characteristics of a high frequency and large amplitude, which is easy to distinguish from the noise signal with the characteristics of a low frequency and small amplitude; and the dispersion of the AE wave velocity measured by the AW method is smaller, which is more suitable for the measurement of the AE wave velocity of an asphalt mixture.
- Development of Piezoelectric Energy Harvester System through Optimizing Multiple Structural ParametersYang, Hailu; Wei, Ya; Zhang, Weidong; Ai, Yibo; Ye, Zhoujing; Wang, Linbing (MDPI, 2021-04-20)Road power generation technology is of significance for constructing smart roads. With a high electromechanical conversion rate and high bearing capacity, the stack piezoelectric transducer is one of the most used structures in road energy harvesting to convert mechanical energy into electrical energy. To further improve the energy generation efficiency of this type of piezoelectric energy harvester (PEH), this study theoretically and experimentally investigated the influences of connection mode, number of stack layers, ratio of height to cross-sectional area and number of units on the power generation performance. Two types of PEHs were designed and verified using a laboratory accelerated pavement testing system. The findings of this study can guide the structural optimization of PEHs to meet different purposes of sensing or energy harvesting.
- Investigation of the Residual Mechanical and Porosity Properties of Cement Mortar under Axial Stress during HeatingGao, Zhifei; Wang, Linbing; Yang, Hailu (MDPI, 2021-04-13)The preload load on concrete during heating is considered to cause a ‘densification’ of cement mortar which led to the increased compressive strength. In order to assess the influence of coupled load and heating effects on porosity characteristics of concrete, the porosity of mortar after mechanical and thermal loading was measured by X-ray computed tomography (X-ray CT). The preload at pre-stress ratios of 0, 0.2, 0.4, and 0.6 (ratio of stress applied to the specimen to its compressive strength at room temperature) were applied on mortar specimens during heating. The residual compressive strengths of the heated and stressed mortar specimens were tested after cooling to room temperature. Combined analyses of the residual compressive strength test results and porosity test results, it shows that the porosity of the specimens under the coupled stressing and heating conditions were slightly lower than that under the unstressed conditions; however, the conclusion that the increase of compressive strength of stressed mortar was caused by the ‘densification’ of cement paste was insufficient. The preload reduced the cracks in the mortar, especially the crack induced due to the thermal mismatch in aggregates and hardened cement paste (HCP), and this may account for the increased compressive strength of stressed mortar.
- Multiscale Analytical Method and Its Parametric Study for Lining Joint Leakage of Shield TunnelWang, Yajian; Yang, Yuyou; Su, Fei; Wang, Linbing (MDPI, 2020-11-28)Understanding the underlying processes of lining joint leakage is essential for predicting its waterproofing performance, improving the design, and assessing its operational health in shield tunnels. There is little literature reported on a leakage model that can reflect various influencing factors. This article introduced an analytical method for predicting joint leakage based on recently developed multi-scale contact mechanics: the Persson model. In addition, the critical leakage state and the self-sealing effect were defined, and an approach to calculate the critical leakage pressure, as well as self-sealing stress, were deduced. Then, taking the second Dapu Road Tunnel in Shanghai as a case study, the influence of various factors, including the gap and offset of joints, the roughness of sealing materials, the service time, and groundwater pressure on the lining joint leakage, was calculated. The applicability of the model was verified by comparing the calculated results with the experimental data and monitoring data in the literature. This research could contribute to understanding the development process of seepage in sealing engineering and provide a reference for waterproof design and the performance assessment of shield tunnels’ lining joints.
- Real-Time and Efficient Traffic Information Acquisition via Pavement Vibration IoT Monitoring SystemYe, Zhoujing; Yan, Guannan; Wei, Ya; Zhou, Bin; Li, Ning; Shen, Shihui; Wang, Linbing (MDPI, 2021-04-10)Traditional road-embedded monitoring systems for traffic monitoring have the disadvantages of a short life, high energy consumption and data redundancy, resulting in insufficient durability and high cost. In order to improve the durability and efficiency of the road-embedded monitoring system, a pavement vibration monitoring system is developed based on the Internet of things (IoT). The system includes multi-acceleration sensing nodes, a gateway, and a cloud platform. The key design principles and technologies of each part of the system are proposed, which provides valuable experience for the application of IoT monitoring technology in road infrastructures. Characterized by low power consumption, distributed computing, and high extensibility properties, the pavement vibration IoT monitoring system can realize the monitoring, transmission, and analysis of pavement vibration signal, and acquires the real-time traffic information. This road-embedded system improves the intellectual capacity of road infrastructure and is conducive to the construction of a new generation of smart roads.