Feedback Design of Temperature Control Measures for Concrete Dams Based on Real-Time Temperature Monitoring and Construction Process Simulation

Huawei Zhou,Yihong Zhou,Chunju Zhao,Fang Wang,Zhipeng Liang 대한토목학회 2018 KSCE Journal of Civil Engineering Vol.22 No.5

Crack prevention is a significant issue in the construction process of concrete dams. The vast majority of concrete cracks arerelated to temperature variations, and hence, temperature control is a primary method used to prevent cracks. This paper presents anew integrated concept, named Feedback Design (FD) of temperature control measures, which incorporates real-time temperaturemonitoring, temperature field simulation and construction process simulation in a large system to optimize a temperature controlscheme for concrete dams. We used a fiber-optic Distributed Temperature Sensing (DTS) system to monitor the temperaturevariation process of typical dam monoliths in real time. By incorporating a genetic algorithm, neural network algorithm, and finiteelement theory, we proposed an intelligent inversion method to obtain thermal parameters of concrete dams based on the temperaturemonitoring data. Meanwhile, we built a simulation model of a concrete dam’s construction process based on a cycling networktechnique to obtain accurate construction environmental parameters. Finally, we simulated the temperature field of a typical dammonolith based on initial temperature control measures, inversion thermal parameters, and accurate construction environmentalparameters. Temperature variance lines of typical points in the model obtained from the finite element method (FEM) accord wellwith the measured values obtained from the DTS system. We applied the FD approach to the Xiluodu arch dam located in southwestChina to forecast the temperature fields and optimize the temperature control scheme of the dam blocks planned for pouring. The FDapproach has been proven reliable and efficacious.

Temperature Field Reconstruction of Concrete Dams based on Distributed Optical Fiber Monitoring Data

Huawei Zhou,Zhiguo Pan,Zhipeng Liang,Chunju Zhao,Yihong Zhou,Fang Wang 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.5

Mastering the real temperature distribution of the concrete dam is the basis for solving the problem of temperature control and crack prevention. In this paper, Distributed Temperature Sensing (DTS) technology was applied to temperature monitoring of a higharch dam under construction in southwest China. In order to obtain a more comprehensive temperature distribution of the dam, optical fiber layout principles for arch dams were studied, and horizontal and vertical optical fiber layout schemes were first proposed according to these principles. The real temperature variation processes of the dam were obtained in real time with a line temperature measurement pattern instead of a point temperature measurement pattern. Additionally, a framework of distributed optical fiber data acquisition and remote transmission was proposed. Interconnection of multiple DTS hosts and remote transmission of temperature data were realized. Then, two-dimensional temperature fields of a typical dam block in different ages and longitudinal profiles of dam blocks with embedded fibers were reconstructed based on large amounts of temperature monitoring data and the Kriging difference algorithm. Temperature field reconstruction results showed that the temperature distribution law of the concrete arch dam was in accordance with the actual situation.

Method and application of spatial positioning for valid temperature-measuring optical fibers in concrete dams

Huawei Zhou,Chunju Zhao,Zhipeng Liang,Yihong Zhou,Fang Wang 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.8

Spatial positioning of Valid Temperature-measuring Optical Fiber (VTOF) is of great significancefor accurately grasping the real temperature distribution of a concrete dam. However, there is barely an effective way to accurately locate the measuring points of optical fiber in concrete dams. A comprehensive data symmetry analysis technique is presented for determining the optimal spatial positioning of valid temperature-measuring optical fibers (VTOFs) in concrete dams. This approach includes a mathematical model to confirm the center of symmetry in monitoring data, which is required to reconstruct the real spatial temperature distribution. This process can identify VTOF locations and verify the reliability of temperature predictions. Experimental validation was conducted using findings from research on a new mathematical model, site measurements from a concrete dam, and corresponding data from distributed optical fibers. These results were successfully applied to the construction of the Baihetan dam; the concrete temperature from 405 pouring blocks in 5 typical dam monoliths was accurately monitored, and the temperature-measuring points of VTOFs were more than 24711. Meanwhile, the optical fiber temperature measurement and temperature field analysis system of Baihetan dam located in southwest China was developed based on accurately acquired temperature measurement data, which provides data basis and engineering application platform support for temperature evolution and temperature field analysis and precise temperature control management of pouring blocks.

A Robust Joint GSS And Source Localization Algorithm For Robot Audition In Strong Reverberant Environment

Huawei Zhang,Chenghao Chen,Yi Zhou 제어로봇시스템학회 2018 제어로봇시스템학회 국제학술대회 논문집 Vol.2018 No.10

The research on robot audition aims to study advanced techniques to help robots acquire acoustic information from the ambient environments. In many real situations, the environment may be adverse like being highly reverberant, and the microphone signal received by the robots may consist of a superposition of several sounds. Geometric source separation (GSS) algorithm uses prior geometric information to separate simultaneously present sound sources and thus is suitable for robot audition applications. However, the performance of GSS deteriorates as the reverberation time increases even if highly accurate sources locations are available, let alone classic source localization (SL) methods themselves can hardly perform well in reverberant environments. In this paper, a joint GSS and SL algorithm is proposed for robot audition applications in strong reverberant environments. This new method estimates the parameters of blind dereverberation (BD), SL and GSS alternatively, which is similar to the conditional separation and dereverberation (CSD) method to release the one-source assumption of many BD algorithms. Furthermore, the proposed method can also be used as a robust SL algorithm alone if necessary. Experimental results verified the robust performance achieved by the proposed algorithm.

Preliminary Study of the Effect of Secondary Airflow on Fiber Attenuation During Melt Blowing

Huawei Xu,Zhijun Zhou,Jie Liu,Lie Zhao,Sheng Xie,Junfeng Zhang 한국섬유공학회 2022 Fibers and polymers Vol.23 No.11

In order to enhance the fiber attenuation during the melt-blown process, a pair of air nozzle, which could eruptairflow as secondary airflow, below the spinning die was arranged and used. Firstly, the effect of applying secondary airflowon the whole airflow was explored by Computational Fluid Dynamics (CFD) simulation. The simulation results demonstratethe interactive relationship between the primary airflow from the spinning die and the secondary airflow. Then, the airvelocity of the whole airflow at conditions of with and without secondary airflow was experimental verified. Finally, theeffect of secondary airflow on the fiber diameter and the fiber evenness was investigated by a spinning experiment. Thespinning results reveals that the application of secondary airflow does not certainly enhance the fiber attenuation. The fiberdiameter decreases only when the inlet velocity of secondary airflow is higher than a critical value. In addition, the spinningexperiment indicates that the application of secondary airflow improves the evenness of fiber.

Development of an immunochromatographic strip for detection of antibodies against porcine reproductive and respiratory syndrome virus

Huawei Li,Jifei Yang,Dengke Bao,Jie Hou,Yubao Zhi,Yanyan Yang,Pengchao Ji,Enmin Zhou,Songlin Qiao,Gaiping Zhang 대한수의학회 2017 Journal of Veterinary Science Vol.18 No.3

A simple and rapid immunochromatographic test strip incorporating a colloidal gold-labeled recombinant Nsp7 antigen probe was successfully developed for the detection of anti-porcine reproductive and respiratory syndrome virus (PRRSV) antibodies in swine. Recombinant Nsp7 protein of PRRSV labeled with colloidal gold was dispensed on a conjugate pad for use as the detector. Staphylococcal protein A and purified porcine anti-Nsp7 antibodies were blotted on a nitrocellulose membrane to form test and control lines, respectively. A comparison of the strip with standard diagnostic tests, enzyme-linked immunosorbent assays and immunoperoxidase monolayer assay, was also performed. The immunochromatographic test strip was shown to be of high specificity and sensitivity. Furthermore, the strip assay is rapid and easy to perform with no requirement for professional-level skills or equipment. It is suggested that the immunochromatographic test strip can be used to quickly and accurately detect PRRSV antibody and to be suitable for diagnostic purposes in the field.

An empirical model for amplitude prediction on VIV-galloping instability of rectangular cylinders

Huawei Niu,Zhengqing Chen,Xugang Hua,Shuai Zhou 한국풍공학회 2015 Wind and Structures, An International Journal (WAS Vol.21 No.1

Aerodynamic forces of vortex-induced vibration and galloping are going to be coupled when their onset velocities are close to each other, which will induce the cross-wind amplitudes of the structures increased continuously with ever-increasing wind velocities. The main purpose of the present work is going to propose an empirical formula to predict the response amplitude of VIV-galloping interaction. Firstly, two typical mathematical models for the coupled oscillations, i.e., Tamura & Shimada model and Parkinson & Corless model are comparatively summarized. Then, the key parameter affecting response amplitude is determined through comparative numerical simulations with Tamura & Shimada model. For rectangular cylinders with the side ratio from 0.5 to 2.5, which are actually prone to develop the VIV and galloping induced interaction responses, an empirical amplitude prediction formula is proposed after regression analysis on comprehensively collected experimental data with the predetermined key parameter.

An empirical model for amplitude prediction on VIV-galloping instability of rectangular cylinders

Niu, Huawei,Zhou, Shuai,Chen, Zhengqing,Hua, Xugang Techno-Press 2015 Wind and Structures, An International Journal (WAS Vol.21 No.1

Aerodynamic forces of vortex-induced vibration and galloping are going to be coupled when their onset velocities are close to each other, which will induce the cross-wind amplitudes of the structures increased continuously with ever-increasing wind velocities. The main purpose of the present work is going to propose an empirical formula to predict the response amplitude of VIV-galloping interaction. Firstly, two typical mathematical models for the coupled oscillations, i.e., Tamura & Shimada model and Parkinson & Corless model are comparatively summarized. Then, the key parameter affecting response amplitude is determined through comparative numerical simulations with Tamura & Shimada model. For rectangular cylinders with the side ratio from 0.5 to 2.5, which are actually prone to develop the VIV and galloping induced interaction responses, an empirical amplitude prediction formula is proposed after regression analysis on comprehensively collected experimental data with the predetermined key parameter.

Investigation on shaping machining method for deep hole keyway based on on-line symmetry detection and compensation

Chunhua Zhao,Zhipeng Liang,Huawei Zhou,Hongling Qin 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.3

Machining of deep hole keyway often suffers from low processing accuracy, low processing symmetry degree between keyway and the reference plane and is difficult to control. In order to enhance the processing quality, a mathematical model of space symmetry error was established based on space projection, orthogonal combination and linear fitting methods so as to study rotatable and shift-able space objects. The space symmetry error was separated into included angle error and displacement error between the fitting straight line and the benchmark line. Through included angle rotation and location measurement along with quantitative translation, the space symmetry error compensation was realized. On the basis of the proposed methods, a Double combined manual self-centering fixture (DCMSF) was designed to realize the radial self-centering and axial location for effective clamping of deep hole keyway, and the reference plane of builtin straight slot was derived out to make it detectable and controllable. Meanwhile, an Online multi-degree of freedom symmetry detection device (OMFSDD) and corresponding Numerical control (NC) programs were also designed for automatic detection and control of symmetry error. Subsequently, mass production of high symmetric deep hole keyway were realized by means of NC gear shaper servo control of rotating shaft angle compensation and bi-directional cutter back-off amount translation compensation, and combination of NC control of fixed angle processing. Deep hole keyway processing experiments indicate that the proposed method can steadily keep the symmetry within 0.03 mm. Thus, the rationality and accuracy of the proposed method was validated which provides a novel approach to high precision deep hole keyway processing.

Assessment Method of Slope Excavation Quality based on Point Cloud Data

Zhiguo Pan,Yihong Zhou,Chunju Zhao,Chao Hu,Huawei Zhou,Yong Fan 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.3

Slope excavation quality assessment is essential in water conservancy engineering. This study presents a quality assessment method to estimate the excavation quality of a slope based on point cloud data obtained from a 3D Terrestrial Laser Scanner (TLS). A data processing method, which includes coordinate registration, data partitioning, and noise removal, is proposed to organize raw data from the TLS and ensure accurate and available point cloud data of a slope surface. An excavation quality assessment method with seven indicators, namely, slope ratio, slope toe elevation, back break, volume of back break, remained semi-void rate, unevenness, and offset degree, is proposed to analyze the difference between a slope’s as-design excavation appearance and actual construction appearance. The as-design excavation appearance is expressed by the Building Information Modeling (BIM) model of a slope-excavation face, and it is a reference to assess the actual construction appearance. The slope excavation quality of a water conservancy project in southwest China is evaluated with the proposed method and the traditional method. The results demonstratethat the proposed method can estimate the slope excavation quality effectively, rapidly, and accuately, and can provide theoretical data support for subsequent work.