Key Technologies of Construction and Control of Arch Cantilever Casting for Mupeng Bridge

2012 ◽  
Vol 204-208 ◽  
pp. 2272-2277 ◽  
Author(s):  
Wen Ping Peng ◽  
Zhong Chu Tian ◽  
Tian Yong Jiang

The technology of cantilever casting construction was complex for reinforced concrete arch bridges. This paper described key technologies of construction and control of concrete arch cantilever casting construction. The article introduced on cast-in-place support, fastening tower, hanging basket and anchorage system in cantilever casting construction. Based on the results of arch ring stress and arch ring camber, the methods of construction control were established on arch ring alignment, arch ring stress, cable force and tower displacement during the arch construction. Ensure the structure safety and make the structure's internal force reasonable, the compressive stress of arch sections is less than 10MPa, tensile stress of arch sections is less than 1.5MPa in construction of concrete arch cantilever casting.

2011 ◽  
Vol 261-263 ◽  
pp. 1778-1783
Author(s):  
Sheng Jun Shao ◽  
Fang Tao She ◽  
Juan Fang

Xi’an ground fracture, caused by the extraction of groundwater and the movement of fault under soil strata, is a geo-hazard. The movement of ground fracture originates the uneven settlement of upward block and downward block. In Xi’an ground fracture region, the segmented lining structure was adopted in subway tunnel to pass through the ground fracture, so as to adapt for the uneven settlement. Three-dimensional elastic-plastic finite difference method was applied to simulate the initial lining structure, second segmented lining structure, surrounding soils and ground fracture. The horizontal and vertical displacement of segmented lining structure, surrounding soils pressure and internal force of segmented lining structure in subway tunnel were analyzed by the calculation results. The knowledge on mechanical behavior of segmented lining structure passing through an active ground fracture and surrounding soils was shown as following. The relative vertical displacement between segmented lining structure sects beside the ground fracture increases remarkably with the movement of ground fracture, and the segmented lining structure located in upward displaceent block near ground fracture originates notable rotary. Tension or compression deformation occured in the deformation joint between adjacent segmented lining structures near the ground fracture.There was a significant change in the contact pressure of the first sect of lining structure in the upward displace block. Under the same uniform settlement at the bottom of upward diaplacement block, the relativly vertical displacemtn on the surfaceof ground fracture strata without tunnel equals 50cm, but the relativly vertical displacement between adjacent segmented lining structure at ground fracture is 18.2cm on the design level of arch top of lining strcutre. the maximum tensile stress of segmented lining structure is 2.02MPa, the maximum compressive stress of segmented lining is 3.49MPa. In conclusion, segmented lining structure can adapts to the uneven settlement caused by the movement of ground fracture. Though maximum tensile and compressive stress of sengmented lining structure passing through the active ground fracture is bigger than the general lining structure located in soils strata without the ground fracture, the segmented lining structure constructed by the steel fibre concrete can bear with the maximum tensile stress.


2011 ◽  
Vol 243-249 ◽  
pp. 335-338
Author(s):  
Jun Feng Guan ◽  
Xiao Ke Li ◽  
Shun Bo Zhao

Former approaches fordesigning reinforced concrete aqueduct with multi-longitudinal beams were mostly based on experience. In this study, an optimization method is proposed instead. According to the mechanical characteristics of aqueduct, optimization principlesfor structural deformation coordination and sectional crack-resisting are developed. Furthermore, in optimization of large and complex reinforced concrete aqueduct, this method employs nominal tensile stress to control the maximum crack width. In addition, a 3D beam-shell element model is suggested for calculating internal force of aqueduct.


2011 ◽  
Vol 243-249 ◽  
pp. 1540-1548
Author(s):  
Yu Zhao ◽  
Jia Le Wei ◽  
Shuan Hai He

Based on the object of self-anchored suspension bridge constructed with long segment hoist method, the load-carrying characteristics and construction technique which is different from other self-anchored suspension bridge is analyzed, and the method of calculation and control on steel box girder configuration during the construction course of long segment hoisted are proposed. For different calculation methods of girder configuration lifting, the influences of the three manners of pre-cambering for steel girders on the configuration and internal force of finished bridge are analyzed. The results show that inverse erection— forward erection—unstressed state synthetic method can guarantee the minimum deviation of steel girder configuration of finished bridge with the design, and it is not necessary to adjust the suspension cable force, and there is no change in main cable configuration and internal force.


2020 ◽  
Vol 29 ◽  
pp. 2633366X2095872
Author(s):  
Yang Wei ◽  
Mengqian Zhou ◽  
Kunpeng Zhao ◽  
Kang Zhao ◽  
Guofen Li

Glulam bamboo has been preliminarily explored for use as a structural building material, and its stress–strain model under axial loading has a fundamental role in the analysis of bamboo components. To study the tension and compression behaviour of glulam bamboo, the bamboo scrimber and laminated bamboo as two kinds of typical glulam bamboo materials were tested under axial loading. Their mechanical behaviour and failure modes were investigated. The results showed that the bamboo scrimber and laminated bamboo have similar failure modes. For tensile failure, bamboo fibres were ruptured with sawtooth failure surfaces shown as brittle failure; for compression failure, the two modes of compression are buckling and compression shear failure. The stress–strain relationship curves of the bamboo scrimber and laminated bamboo are also similar. The tensile stress–strain curves showed a linear relationship, and the compressive stress–strain curves can be divided into three stages: elastic, elastoplastic and post-yield. Based on the test results, the stress–strain model was proposed for glulam bamboo, in which a linear equation was used to describe the tensile stress–strain relationship and the Richard–Abbott model was employed to model the compressive stress–strain relationship. A comparison with the experimental results shows that the predicted results are in good agreement with the experimental curves.


2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Sahar Y. Ghanem ◽  
Heba Elgazzar

AbstractFiber Reinforced Polymer (FRP) usage to wrap reinforced concrete (RC) structures has become a popular technology. Most studies about RC columns wrapped with FRP in literature ignored the internal steel reinforcement. This paper aims to develop a model for the axial compressive strength and axial strain for FRP confined concrete columns with internal steel reinforcement. The impact of FRP, Transverse, and longitudinal reinforcement is studied. Two non-destructive analysis methods are explored: Artificial Neural Networks (ANNs) and Regression Analysis (RA). The database used in the analysis contains the experimental results of sixty-four concrete columns under the compressive concentric load available in the literature. The results show that both models can predict the column's compressive stress and strain reasonably with low error and high accuracy. FRP has the highest effect on the confined compressive stress and strain compared to other materials. While the longitudinal steel actively contributes to the compressive strength, and the transverse steel actively contributes to the compressive strain.


2021 ◽  
Vol 245 ◽  
pp. 112898
Author(s):  
Ladislav Klusáček ◽  
Radim Nečas ◽  
Michal Požár ◽  
Robin Pěkník ◽  
Adam Svoboda

1979 ◽  
Vol 105 (2) ◽  
pp. 313-326 ◽  
Author(s):  
Paola Ronca ◽  
M. Z. Cohn

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