scholarly journals Radial Joints Behavior of a Precast Asymmetric Underpass Induced by Long-Term Loads of Ground Vehicles

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Zhiyi Jin ◽  
Taiyue Qi ◽  
Xiao Liang ◽  
Bo Lei ◽  
Yangyang Yu ◽  
...  
Keyword(s):  
Transient Response ◽  
Model Test ◽  
Similarity Theory ◽  
Rapid Development ◽  
Design Stage ◽  
Physical Model Test ◽  
Scaled Model ◽  
Joint Opening ◽  
Assembly Technology

With the rapid development of the urbanization, many underpasses are designed and constructed in big cities to alleviate the huge traffic pressure. The construction method has been changed from traditional on-site concrete pouring technology to prefabricated assembly technology. However, this change will inevitably bring out some new problems to be studied such as the behaviour of the radial joints. In this study, the numerical simulation model of Moziqiao precast and assemble underpass with large asymmetric cross section was constructed by using the ABAQUS software to study the transient response of the underpass induced by ground surface dynamic load. Based on the similarity theory a 1/10 scaled model test was carried out to study the long-term radial joint behaviour of the underpass considering the prestress loss during the 2000 000 loading cycles. The results transient dynamic response from computed and tested was compared in terms of acceleration. The comparison showed that the transient response accelerations have good consistency. The results of the physical model test were analysed in terms of joint opening, closure, and slipping. The accumulative joint opening was closely correlated to the prestress level, and the joint opening at different prestress levels increased with the loss of the prestress. The joints closure decreased with the increase of the previous accumulative color value. The joint slipping mainly attributed to the slipping of the top segment. Both the opening and slipping of the joints at RJ 1 were larger than that of RJ3 due to the wider span of RJ1, which reflected an asymmetric effect. This study revealed the long-term accumulative behaviour of the radial joints, which convinced us that the long-term accumulative deformation of the joints should be taken into consideration during the design stage for similar projects.

scholarly journals Correction of Earth Pressure and Analysis of Deformation for Double-Row Piles in Foundation Excavation in Changchun of China

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Yijun Zhou ◽  
Aijun Yao ◽  
Haobo Li ◽  
Xuan Zheng
Keyword(s):  
Physical Model ◽  
Model Test ◽  
Large Scale ◽  
Similarity Theory ◽  
Earth Pressure ◽  
Physical Model Test ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Double Row ◽  
The Earth

In order to study the earth pressure and the deformation behavior of the double-row piles in foundation excavation, a large-scale physical model test was introduced to simulate deformation of double-row piles in foundation excavation based on the principle of similarity theory in this paper. Represented by the deep foundation pit engineering of Changchun, the strain and the displacement of the double-row piles and the earth pressure are calculated by the above-mentioned physical model test. Then a numerical simulation has been carried out to validate practicability of the physical model test. The results show that the strain and the displacement of the front-row piles are larger than the back-row piles. The earth pressure of the front-row piles appears to be “right convex,” correcting the specification of the earth pressure and putting forward the coefficient of β. The results in this paper may provide constructive reference for practical engineering.

scholarly journals Experimental Study of Dowel Bar Alternatives Based on Similarity Model Test

2017 ◽  
Vol 2017 ◽  
pp. 1-9
Author(s):  
Chichun Hu ◽  
Jiexian Ma ◽  
Jianying Zhao ◽  
Zhen Leng ◽  
Denis Jelagin
Keyword(s):  
Model Test ◽  
Load Transfer ◽  
Similarity Theory ◽  
Concrete Specimen ◽  
Transfer Efficiency ◽  
Loading Test ◽  
Scaled Model ◽  
Similarity Model ◽  
Bearing Stress ◽  
Load Transfer Efficiency

In this study, a small-scaled accelerated loading test based on similarity theory and Accelerated Pavement Analyzer was developed to evaluate dowel bars with different materials and cross-sections. Jointed concrete specimen consisting of one dowel was designed as scaled model for the test, and each specimen was subjected to 864 thousand loading cycles. Deflections between jointed slabs were measured with dial indicators, and strains of the dowel bars were monitored with strain gauges. The load transfer efficiency, differential deflection, and dowel-concrete bearing stress for each case were calculated from these measurements. The test results indicated that the effect of the dowel modulus on load transfer efficiency can be characterized based on the similarity model test developed in the study. Moreover, round steel dowel was found to have similar performance to larger FRP dowel, and elliptical dowel can be preferentially considered in practice.

scholarly journals Time-Based Corporate-Social-Responsibility Evaluation Model Taking Chinese Listed Forestry Companies as an Example

2021 ◽  
Vol 13 (14) ◽  
pp. 7971
Author(s):  
Xinfei Li ◽  
Baodong Cheng ◽  
Heng Xu
Keyword(s):  
Corporate Social Responsibility ◽  
Social Responsibility ◽  
Evaluation Model ◽  
Rapid Development ◽  
Entropy Method ◽  
Static State ◽  
Different Types ◽  
Normative Constraints ◽  
Corporate Social

With the rapid development of the economy, corporate social responsibility (CSR) is receiving increasing attention from companies themselves, but also increasing attention from society as a whole. How to reasonably evaluate the performance of CSR is a current research hotspot. Existing corporate-social-responsibility evaluation methods mostly focus on the static evaluation of enterprises in the industry, and do not take the time factor into account, which cannot reflect the performance of long-term CSR. On this basis, this article proposes a time-based entropy method that can evaluate long-term changes in CSR. Studies have shown that the completion of CSR in a static state does not necessarily reflect the dynamic and increasing trend of CSR in the long term. Therefore, the assessment of CSR should consider both the static and dynamic aspects of a company. In addition, the research provides the focus of different types of forestry enterprises in fulfilling CSR in the long term, and provides a clearer information path for the standard identification and normative constraints of different types of forestry enterprises CSR.

scholarly journals Rotor Loading Characteristics of a Full-Scale Tidal Turbine

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1035 ◽  
Author(s):  
Magnus Harrold ◽  
Pablo Ouro
Keyword(s):  
Turbulent Flows ◽  
Mechanical Loading ◽  
Full Scale ◽  
Design Stage ◽  
Flow Profile ◽  
Expected Return ◽  
Tidal Turbines ◽  
Theoretical Predictions ◽  
Tidal Turbine

Tidal turbines are subject to highly dynamic mechanical loading through operation in some of the most energetic waters. If these loads cannot be accurately quantified at the design stage, turbine developers run the risk of a major failure, or must choose to conservatively over-engineer the device at additional cost. Both of these scenarios have consequences on the expected return from the project. Despite an extensive amount of research on the mechanical loading of model scale tidal turbines, very little is known from full-scale devices operating in real sea conditions. This paper addresses this by reporting on the rotor loads measured on a 400 kW tidal turbine. The results obtained during ebb tidal conditions were found to agree well with theoretical predictions of rotor loading, but the measurements during flood were lower than expected. This is believed to be due to a disturbance in the approaching flood flow created by the turbine frame geometry, and, to a lesser extent, the non-typical vertical flow profile during this tidal phase. These findings outline the necessity to quantify the characteristics of the turbulent flows at sea sites during the entire tidal cycle to ensure the long-term integrity of the deployed tidal turbines.

Measuring Dynamic Sales Impacts of LBA Using Wireless Communication Technology

2013 ◽  
Vol 662 ◽  
pp. 896-901
Author(s):  
Zong Jin Liu ◽  
Yang Yang ◽  
Zheng Fang ◽  
Yan Yan Xu
Keyword(s):  
Wireless Communication ◽  
Error Correction ◽  
Communication Technology ◽  
Dynamic Error ◽  
Rapid Development ◽  
Vector Autoregressive ◽  
Vector Error Correction ◽  
Vector Error ◽  
Equilibrium Relationship

Because of rapid development of wireless communication technology, there is an increasing adoption of mobile advertising, such as location based advertising (LBA). To what extent can LBA improve advertising effectiveness is an important topic in the field of wireless communication technology research. Most researches quantify long term impacts of advertisings by VAR (Vector Autoregressive) model. However, compared to VAR model, VECM (Vector Error Correction Model) is a better method in that it allows one to estimate both a long-term equilibrium relationship and a short-term dynamic error correction process. In this study, we employ VECM to explore LBA’s (Location Based Advertising) and PUA’s (Pop-up Advertising) sales impact in both short and long terms. The developed VECM reveals that LBA’s sales impact is about more than2 times as big as PUA’s in short dynamic term and nearly 6 times bigger than PUA’s in long equilibrium term. These findings add to advertising and VECM literatures. These results can give managers more confident to apply wireless communication technology to advertising.

The PLC Research in the Program Control System of Thermal Power Coal Handling

2012 ◽  
Vol 548 ◽  
pp. 812-816
Author(s):  
Xiao Min Chen ◽  
Xi Yan Liu
Keyword(s):  
Power Plants ◽  
Rapid Development ◽  
Thermal Power ◽  
Chinese Economy ◽  
Power Requirement ◽  
Handling System ◽  
Human Power ◽  
Material Resources ◽  
Electricity System

With the rapid development of Chinese economy, the thermal power requirement is increasing not only in industry but also for the civil use in recent years. In China, the main fuel of thermal power is coal. Coal handling system places the consequence in the whole generate electricity system and has significant meaning to the power plant operation. The coal handling system of the thermal power plants has many types of equipment. The environment is vile with complicated control. If we control this system through manual mode, there will appear the imponderable questions. This article through the research of the coal handling system by the management of PLC can determine the long-term safe operation and reduce a mass of human power and material resources. It has the fundamental practical meaning and research value.

Long-Term Mean Wind Profiles Based on Similarity Theory

2010 ◽  
Vol 136 (3) ◽  
pp. 377-390 ◽  
Author(s):  
Mark Kelly ◽  
Sven-Erik Gryning
Keyword(s):  
Similarity Theory ◽  
Wind Profiles
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