Influence of Closure Sequences on the Rigid Frame-Continuous Girder Bridge Closure

2013 ◽  
Vol 361-363 ◽  
pp. 1422-1428 ◽  
Author(s):  
Zhan Yong Yao ◽  
Xiao Meng Zhang ◽  
Shuai Li ◽  
Lian Fu Li ◽  
Xiang Hong Pan ◽  
...  

Closure sequences of rigid frame-continuous girder bridge are analyzed by calculation to compare girder deflection change, pier horizontal displacement maximum, girder and pier stress value. The results show that the first side span-second side span-mid span closure sequence causes the largest girder vertical displacement and others cause almost the same vertical displacement; side piers pier top horizontal displacement is larger than middle piers whatever the closure sequence is, closure sequences could not change the stress of the girder and pier. The first side span-mid span-second side span closure sequence should be preferred.

2011 ◽  
Vol 243-249 ◽  
pp. 1928-1934 ◽  
Author(s):  
Tian Bo Peng ◽  
Zhen Nan Wang ◽  
Xun Tao Yu ◽  
Cheng Yu Yang

The double spherical seismic isolation (DSSI for short) bearing has been adopted in seismic design of several important engineering projects since developed recently. It was used generally as fixed bearings in a continuous girder bridge in these projects, and only a few fixed piers, usually just one fixed pier would transmit the horizontal earthquake action to the foundation, which is uneconomical and results in the much larger seismic risk in the longitudinal direction of a continuous girder bridge than that in the transverse direction. In order to share the earthquake effect with all the piers and avoid relative vertical displacement among all the bearings under the normal traffic conditions, a new seismic design method of continuous girder bridges is introduced. The configuration and working mechanism of two kinds of DSSI bearings used to make the new seismic design possible are introduced. It’s shown that the method is preferable for the seismic design of continuous girder bridges by a numerical seismic analysis with a four-span continuous girder bridge.


2014 ◽  
Vol 8 (1) ◽  
pp. 416-419
Author(s):  
Lifeng Wang ◽  
Hongwei Jiang ◽  
Dongpo He

Deflection control is the crucial procedure in construction control of cantilever prestressed concrete continuous girder bridge. This paper summarizes the advantages of Grey theory’s poor information processing and abilities of Neural Network’s self-learning and adaption, and the combinational algorithm of grey Neural Network is applied to the prestressed concrete bridge cantilever construction control process. Firstly, GM (1, 1) model and BP artificial Neural Network algorithm to predict the elevation of construction process are introduced respectively. In addition, the elevation prediction model of rigid-framed-continuous girder bridge is established. By practicing in the construction control project of LongHua Bridge, the method is testified to be feasible. The results indicate that, the combinational algorithm of Gray Neural Network to predict the construction elevation has higher reliability and accuracy which can be an effective tool of construction control for the same type bridges.


2021 ◽  
Vol 75 ◽  
pp. 102844
Author(s):  
Yan Liang ◽  
Jia Lei Yan ◽  
Wei Xin Qian ◽  
Zhan Qi Cheng ◽  
Huai Chen

2010 ◽  
Vol 163-167 ◽  
pp. 4165-4169
Author(s):  
Wen Liang Qiu ◽  
Le Zhou ◽  
Yu Zhang

Based on the shortcomings of the continuous girder bridge with single column pier, two-span T-shape rigid-frame bridges with single integral pier and two separated piers are put forward in this paper. Using time-history analysis and considering the material nonlinearity of reinforced concrete of the pier, the nonlinear seismic responses of the three bridge structures subjected to horizontal seismic wave are analyzed. The results show that, compared with continuous girder bridge, the shear forces of the two types of T-shape rigid-frame bridge are bigger, the moments of the T-shape rigid-frame bridges is smaller, and rotation angle of plastic hinge of T-shape rigid-frame bridge is much smaller. The energy dissipation and the anti-seismic capacities of T-shape rigid-frame bridges are better than continuous girder bridge under the condition that the shear resistance capacity of pier is secure.


2013 ◽  
Vol 838-841 ◽  
pp. 1082-1086
Author(s):  
Xue Xian Sun ◽  
Zhen Liu

This paper apply displacement back analysis theory for geometry form monitoring and calculating work of segmental construction of prestressed concrete continuous girder bridge, making use of displacement back analysis method to optimize bridge structure parameters, ensuring accuracy of geometry form control with calculated results of every girder segment in entire construction. This method is used in the construction monitoring and supervision for Yuanyichang circular curved rigid frame bridge on Pingan-Adai highway, to make the closure accuracy and the bridge geometry form reaches the effect of aspiration. Through the result of the finished bridge, what we can obtain is that the displacement back analysis theory could fulfill the requirement of factual project and be widely used for geometry monitoring of segmental construction of prestressed concrete continuous girder bridge.


2014 ◽  
Vol 501-504 ◽  
pp. 1182-1186 ◽  
Author(s):  
Kong Jian Shen ◽  
Pei Feng Li ◽  
Qiao Wang ◽  
Shui Wan

This paper presents a survey of construction techniques for pre-stressed concrete (PC) box-girder bridge with corrugated steel webs in recent decades. The structural forms of the bridge have experienced simply supported beam bridge, continuous girder bridge, cable-stayed bridge and the continuous rigid frame bridge. Meanwhile, the construction technologies were constantly innovated, including cast-in-situ, precast and the combination of them. The processing and installation technologies of corrugated steel webs and several typical construction techniques for PC box-girder with corrugated steel webs were elaborated, such as full framing construction, cantilever construction, span-by-span construction, incremental launching construction and some other various innovative ways. The valuable experiences in a variety of construction methods were summed up. The results show that some innovative construction ways should be developed by fully utilizing the corrugated steel webs as a guide beam or a work platform to improve the efficiency of construction.


Author(s):  
Qiwen Jin ◽  
Zheng Liu

In-service bridges, under long-term service operational environment, are usually accompanied by different damage types. Traditional method for the measure point arrangement of in-service bridge SHM is usually based on engineering experience. A large number of SHM sensors are usually arranged on the structure, followed by a high engineering cost and a heavy maintenance task. These sensors will also produce large amounts of data, creating a challenge for operators requiring to deal with data processing in an effective manner. This study serves as a part of the series of studies on the measure point arrangement strategy of in-service bridge SHM. In this study, the SHM sensor measure point arrangement of in-service continuous girder bridge (a common structural style of high way bridge in China) is proposed. Two-span continuous beam, three-span continuous beam, and four-span continuous beam are taken as examples. Detailed comparison and verification are also performed with consideration of numerical simulation and previous studies. Different traffic speeds and different bridge spans are considered. The effect of different damage locations and different damage degrees are analyzed in detail. This study shows that a general similar trend can be observed for the structural robustness of in-service continuous girder bridge. The elements with smaller structural robustness of this kind of bridge are basically located around the middle cross section of side spans (first span and last span), followed by the middle span. Moreover, the numerical value of structural robustness of different elements in a continuous girder bridge is significantly different from each other, due to the complexity of the joint effect of different traffic speeds and damage locations. Therefore, the measure point should be generally arranged at the side span firstly, followed by the middle span. With consideration of the specific traffic speed and damage location in engineering application, a detailed analysis is also proposed for the further optimization of SHM sensor measure point arrangement. Once the elements are arranged in order of the numerical value of structural robustness, the SHM sensor measure point arrangement of this kind of bridge can be more targeted, and the number of sensors can also be greatly reduced.


2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Toshifumi Nogawa ◽  
Masayasu Saito ◽  
Naomichi Murashima ◽  
Yoshiyuki Takayama ◽  
Atsuro Yokoyama

Abstract Background Implant-supported removable partial dentures (ISRPDs) are an effective treatment for partially edentulous patients. ISRPDs improve patients’ satisfaction and oral function to a greater extent than RPDs by improving denture stability and enhancing support. However, the effect of a type of direct retainer on displacement of the abutment teeth and dentures in ISRPDs remains unclear. Therefore, we made a resin mandibular model of unilateral mandibular distal-extension partial edentulism for mechanical simulation and compared the dynamic behavior of the abutment teeth and the denture base among different tooth-borne retainers with various rigidities for RPDs and ISRPDs. Methods A resin mandibular model for mechanical simulation that had unilateral mandibular distal-extension edentulism and was missing the first molar, second molar, first premolar, and second premolar, and a denture fabricated from the patient’s computed tomography images were used. Three types of direct retainers with different connecting rigidities were evaluated. The vertical displacement of the denture base and buccal and lingual sides and the mesial displacement of the abutment teeth were measured. Results Regardless of the rigidity of the direct retainers and loading positions, the displacement of the denture bases in the ISRPDs was significantly smaller than that in the RPDs (P < 0.001). There was no significant difference in vertical displacement of the denture bases among direct retainers with various connecting rigidities in the ISRPDs. Conversely, horizontal displacement of the abutment teeth in both the RPDs and ISRPDs tended to be larger with the cone crown telescope, which has high rigidity, than with the cast cingulum rest and wire clasp, which have much lower rigidities. Conclusion Our results suggested that cast cingulum rest and wire clasps as direct retainers are appropriate ISRPDs to minimize denture movement and suppress displacement of the remaining teeth in patients with unilateral mandibular distal-extension partial edentulism.


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