Study on Optimizing Installation Technology of Movable Steel Guardrails in Reconstruction and Expansion Projects of Expressways

Author(s):  
Wanli Tian ◽  
Zhongguang Wu ◽  
Shuo Pan ◽  
Jing Chen ◽  
Zhenhu Zhang
Geosciences ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 41
Author(s):  
Tim Jurisch ◽  
Stefan Cantré ◽  
Fokke Saathoff

A variety of studies recently proved the applicability of different dried, fine-grained dredged materials as replacement material for erosion-resistant sea dike covers. In Rostock, Germany, a large-scale field experiment was conducted, in which different dredged materials were tested with regard to installation technology, stability, turf development, infiltration, and erosion resistance. The infiltration experiments to study the development of a seepage line in the dike body showed unexpected measurement results. Due to the high complexity of the problem, standard geo-hydraulic models proved to be unable to analyze these results. Therefore, different methods of inverse infiltration modeling were applied, such as the parameter estimation tool (PEST) and the AMALGAM algorithm. In the paper, the two approaches are compared and discussed. A sensitivity analysis proved the presumption of a non-linear model behavior for the infiltration problem and the Eigenvalue ratio indicates that the dike infiltration is an ill-posed problem. Although this complicates the inverse modeling (e.g., termination in local minima), parameter sets close to an optimum were found with both the PEST and the AMALGAM algorithms. Together with the field measurement data, this information supports the rating of the effective material properties of the applied dredged materials used as dike cover material.


Author(s):  
Ze Li ◽  
Li Li Wang ◽  
Subin Subin Li ◽  
Xinjing Xinjing Zhang ◽  
Guosen Zhou

With the rapid development of China's overall economy, the construction engineering industry is gradually improving. Architectural engineering is an important environment for people to live, and its quality and safety are directly related to people's life and property. The most important part of the construction project is the mechanical and electrical installation, to realize the cost control of the project is the key point of the project. This article mainly explains the mechanical and electrical installation engineering in building engineering, and introduces the installation and construction technology in mechanical and electrical installation engineering in detail, and analyzes the control difficulties. It provides an important reference for the management of mechanical and electrical installation technology in the future.


2016 ◽  
Vol 8 (5) ◽  
pp. 495-498
Author(s):  
Tautvydas Statkus

In this article jacked pile installation technology and its current processes, altering the base physical and mechanical characteristics are discussed. For the jacked pile static load test simulation Plax 3D software was selected, the opportunities and developments were described. Model building, materials, models, model geometry, finite elements, boundary conditions and assumptions adopted in addressing problems described in detail. Three different tasks formulated and load-settlement dependence a comparison of the results with the experiment given. Conclusions are formulated according to the modeling results. Šiame straipsnyje aptarta spaustinių polių įrengimo technologija ir ją taikant vykstantys procesai, keičiantys pagrindo fizines ir mechanines charakteristikas. Spaustinio polio bandymui statine apkrova modeliuoti pasirinktas PLAXIS 3D programinis paketas ir aprašytos jo galimybės bei raida. Detaliai nupasakotas modelio kūrimas, medžiagų modeliai, modelio geometrija, baigtiniai elementai, kraštinės sąlygos ir priimamos prielaidos sprendžiant problemą. Suformuluoti trys sprendžiami uždaviniai ir apkrovos bei nuosėdžio priklausomybe pateikiamas rezultatų palyginimas su eksperimentu. Atsižvelgiant į modeliavimo rezultatus suformuluotos išvados.


Author(s):  
Peng Wang ◽  
Xiao Wu ◽  
Wenyue Lu ◽  
Xinliang Tian ◽  
Xin Li

Floatover method has been proven a competitive installation technology in last thirty years. However, floatover installation is subject to a variety of technical challenges. Apart from weather restrictions, motions and position of the topside and deck transport vessel (DTV) should be strictly controlled during the entire installation operations. Therefore, a field monitoring system is essential to guarantee the installation safety. In this paper, a comprehensive introduction to the monitoring system developed by Shanghai Jiao Tong University is presented. The subsystems, including environment monitoring system, motions and position monitoring system, deck support units (DSUs) separating monitoring system, closed-circuit-television (CCTV) monitoring system as well as the integrated monitoring system (IMS), are proposed. Besides, the pre-installation surveys are also presented.


2012 ◽  
Vol 204-208 ◽  
pp. 2209-2213 ◽  
Author(s):  
Ya Jiang Du ◽  
Bing Wen Yang ◽  
Shui Wan

In the construction of prestressed concrete(PC) box-girder bridge with corrugated steel webs used cast-in-place cantilever method, the key component-corrugated steel webs are fabricated in factory first and then transported to the construction site. Because of the low out-of plane stiffness, corrugated steel webs are easy to deform in the construction, which brings many difficulties for construction. The precision of installing the corrugated steel web has a direct effect on the cross-section shape of the box-girder. So it is a key step to monitor the orientation and installation of corrugated steel web during construction. Based on the experience of some PC box-girder bridges with corrugated steel webs having been built, a method to control the installation accuracy of corrugated steel webs is proposed and some quality assurance measures are introduced in order to ensure the accuracy, reliability and security of the installation of corrugated steel web. The method can be taken as a reference in the construction of this kind of bridge.


Energies ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 23
Author(s):  
Jijian Lian ◽  
Pengwen Wang ◽  
Conghuan Le ◽  
Xiaofeng Dong ◽  
Xu Yang ◽  
...  

Composite bucket foundations, which have been successfully transported, installed, and operated at the Qidong, Xiangshui, and Dafeng offshore wind farms in China, are economically advantageous due to the relatively simple transportation and installation process. The innovative one-step transportation and installation technology of foundation-tower-nacelle is the key phase in saving costs. In this paper, a “foundation lift ship” overall transport mode is proposed and introduced for the first time. Prototype data measurement, preliminary numerical simulation, and theoretical calculations were conducted to investigate whether the foundation-ship integrity, tower hoop stability, and various indexes of the nacelle met the requirements under the influences of various environmental factors. The multi-system coupling motion mechanism and analysis method of this new structure and transportation mode were expounded. Through the prototype observation data of the one-step overall transportation, the ship-foundation system reliability of the structure in the case of large wind and wave was confirmed. Furthermore, it was found that in the one-step overall transportation, the importance of factors to nacelle acceleration decreased in the order of wave height, current speed, and wind speed by the time and frequency domain analysis and data statistics.


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