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Meng J.,T. Y. Lin International Engineering Consulting China Co. | Liu Z.,Nanjing Southeast University
Zhendong yu Chongji/Journal of Vibration and Shock | Year: 2013

Considering the irregular geometry, stiffness and mass distribution, the critical angle of seismic incidence for curved bridges was investigated. The yield condition for concrete structure under axial compression and bi-axial flexural moments were well depicted with Bresler Yield Surface, the most vulnerable direction for piers was therefore defined as the critical angle of seismic incidence. Based on obtaining the seismic responses in two orthotropic directions with the response spectrum analysis, a new algorithm was proposed considering multicomponent ground motion and the correlation of natural vibration modes. Furthermore, procedures for time history analysis were developed. Finally, an example of a closed circular ramp was given to illustrate the validity of the method.

Wu W.,CAS Wuhan Institute of Rock and Soil Mechanics | Wu W.,TYLin International Engineering Consulting China Co. | Feng X.,CAS Wuhan Institute of Rock and Soil Mechanics | Zhang C.,CAS Wuhan Institute of Rock and Soil Mechanics | Qiu S.,CAS Wuhan Institute of Rock and Soil Mechanics
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2011

According to the geological conditions, field test, numerical analysis and the entire process of supporting design and construction of tunnels in Jinping II hydropower station, a classification method for failure modes of surrounding rock of deep tunnel in hard rock is established. All of failure phenomena are divided into 3 categories and 9 typical failure modes by the proposed method respectively based on demands of supporting and controlling factors. Furthermore, failure mechanisms and manifestations are analyzed;and controlling measures are provided. Specially, the mechanisms and corresponding controlling measures of rockbursts are discussed. The classification method is applied to identify and analyze various kinds of failure modes, all of which are revealed during excavation of tunnels in Jinping II hydropower station. The recommended controlling measures are adopted referring to the failure modes. The engineering practice indicates that the classification method is comprehensive and practical, which provides an effective way for on-site designers, geologists and constructors to optimize excavation and supporting design of deep tunnel in hard rock.

Qian Z.,Nanjing Southeast University | Chen L.,Nanjing Southeast University | Jiang C.,T.Y.Lin International Engineering Consulting China Co. | Luo S.,Nanjing Southeast University
Construction and Building Materials | Year: 2011

This paper proposes a lightweight epoxy asphalt mixture (LEAM) for pavement on bascule bridges. The material properties of LEAM are evaluated with the Marshall test, indirect tensile test, wheel tracking test, and bending beam test. Moreover, the structural performance of LEAM is evaluated by a finite element numerical analysis for a bascule bridge with LEAM pavement. Test results show that the LEAM has a good resistance to moisture damage, permanent deformation, and low-temperature cracking. The LEAM with a 70% lightweight aggregate replacement percentage has been found to have the best effect on deadweight reduction as well as the other performance measures. Moreover, the analytical result shows that LEAM can reduce pavement stress significantly when compared to an epoxy asphalt mixture, which indicates that the LEAM has a good structural performance. © 2010 Elsevier Ltd. All rights reserved.

Qian Z.,Nanjing Southeast University | Chen C.,Nanjing Southeast University | Jiang C.,T.Y. Lin International Engineering Consulting China Co. | Smit A.D.F.,University of Texas at Austin
Construction and Building Materials | Year: 2013

A lightweight epoxy asphalt mixture (LEAM) was developed by replacing part of the basalt aggregate in an epoxy asphalt mixture with lightweight aggregate. These mixtures were evaluated as alternative to basalt mixes for deck paving of the TianJin bascule bridge in China. Nine different types of LEAM with varying lightweight aggregate shapes and percentages were designed and tested. The results indicated significant variations in performance. This approach was deemed viable based on FEM analyses that indicated significant stress reductions using lightweight material. Based on the findings it is recommended that a LEAM with 70% rounded lightweight aggregate be used to reduce the deadweight of the deck paving and optimize performance in terms of rutting and cracking resistance. © 2013 Elsevier Ltd. All rights reserved.

Wu X.R.,Chinese Research Institute of Highway | Zhu L.L.,T. Y. Lin International Engineering Consulting China Co
Advanced Materials Research | Year: 2014

The loess test road of four highways in Shanxi Province selected. Through the contrast and analysis the data of resilient modulus and CBR on field, the paper presents the conversion relationship between resilient modulus and CBR for north and south shanxi province. The conversion relationships provide reliable basis for the resign of pavement construction. © (2014) Trans Tech Publications, Switzerland.

Lan Z.-B.,T. Y. Lin International Engineering Consulting China Co. | Li M.-N.,T. Y. Lin International Engineering Consulting China Co.
Bridge Construction | Year: 2014

The span arrangement of the continuous unit 2 (Piers MP4~MP6) of Ramp M of the Huangjuewan Interchange in Nan'an District, Chongqing City is (22+27) m. The designed radius of the unit is 50 m, the longitudinal slope is 5.4% and the transverse slope is 6%. The unit is a prefabricated steel box girder that was erected by the integral lifting and installing method. After the girder was installed in place, it was found that the inner side bearings on the Piers MP4 and MP6 disengaged from the girder. To ensure the future safe operation of the bridge, the bearing disengagement was handled. The analysis of the bearing disengagement showed that the cause of the disengagement was that the spatial torsion condition of the girder was not considered in the prefabrication and the girder was processed only in one horizontal plane. In regard of the cause of the disengagement and the actual shape of the girder, the disengagement was handled by the scheme of integrally rotating the girder, redetermining the elevation of all the bearings and making the reaction force values of the bearings meet the design requirements. In the handling of the bearing disengagement, the girder was synchronously jacked up and was made to rest on the bearings and finally the target of the handling of the disengagement was achieved as expected. ©, 2014, Wuhan Bridge Research Institute. All right reserved.

Tian W.,Chongqing University | Saeed A.T.,T.Y.Lin International Engineering Consulting China Co. | Yang J.,House and Urban Bureau of Lixian
Journal of Convergence Information Technology | Year: 2012

The cantilever construction method with non-framework cable hoisting erection for arch bridge is gaining popularity in recent years. The final stresses and deformations in a finished arch bridge are strongly dependent on the sequence of events during the construction and the erection procedure being used. Therefore, calculation of cable tension is an important step in any analysis of the performance of the bridge at the actual construction sequence. In this paper a method for calculation of tension in cables for construction of arch bridge using perturbation is presented, and it is applied in the construction of Daninghe Bridge to ensure that the arch rib is constructed to line and level. Interestingly, the proposed method is more accurate and shows faster convergence than the common cyclic method.

Lai Y.-P.,T.Y. Lin International Engineering Consulting China Co. | Wang K.,T.Y. Lin International Engineering Consulting China Co. | Li J.,T.Y. Lin International Engineering Consulting China Co.
Bridge Construction | Year: 2016

The main bridge of the Fourth Luzhou Tuojiang River Bridge is a hybrid girder cable-stayed bridge with a single pylon, double cable planes and with span arrangement (55+200+58+50) m and deck width of 49 m. In the recent future, the bridge will serve as a dual 4-lane roadway bridge and in the far future, will be retrofitted into a dual 3-lane+2-track road-cum-light rail bridge. To satisfy the operation of the bridge in both the recent and far future, the critical design techniques of the bridge were researched, using the finite element method. The spatial spine beam model for the bridge was established and the torsional characteristics of the main girder under the eccentric load were studied. The spatial finite element model for the steel and concrete box girders was also established and the shear lag effect of the girders was analyzed. Through the comparison of the 3 schemes prepared for the girders, the location of the steel and concrete joint section of the main girder was determined and the joint section was structurally optimized and through the calculation and analysis, the mechanical properties of the exposing type steel anchor box anchorage structure in the steel and concrete composite pylon of the bridge were studied. The results demonstrate that under the eccentric load, the maximum shear stress and torsional angle of the main girder can satisfy the relevant requirements in the codes. The shear lag effect of the steel box girder is obvious, but the effect of the concrete box girder is relatively not. When the joint section is arranged at 8.5 m from the pylon center on the side of the central span, the deformation and in ternal forces of the section are little. The utilization of the new type of the anchorage structure in the composite pylon of the bridge can bring the material properties into full play and can ensure the safety of the pylon. © 2016, Journal Press, China Railway Bridge Science. All right reserved.

Yin D.-L.,T.Y. Lin International Engineering Consulting China Co. | Deng Y.,T.Y. Lin International Engineering Consulting China Co.
Bridge Construction | Year: 2013

To illustrate the importance of the redundancy concept in bridge design, the redundancy concept in the bridge design is introduced from aspect of response of the integral structure of a bridge to the failure of a local single component of the bridge according to the bridge failure cases and further, 3 forms of expressions of the redundancy of the bridge system, such as the internal redundancy, structural redundancy and load transferring path redundancy, are analyzed. In terms of the review of the research findings of the Transportation Research Board on the redundancy in the bridge design over the years, the special provisions, the connection between the fracture sensitivity and redundancy in the steel bridge design, are summarized and the relevant suggestions on application of the redundancy in the design principle are made as follows: 1) the structural type that is continuous and with good integrity should be used wherever possible; 2) in the codes for the bridge design, the redundancy requirements of the bridges for the particular events (such as the earthquake) should be specifically formulated and 3) when the very long span bridges are designed, the multiple load transferring paths should be possibly provided for the design of the critical components.

Yang M.-G.,Central South University | Li C.-Y.,T.Y. Lin International Engineering Consulting China Co. | Chen Z.-Q.,Hunan University
Engineering Structures | Year: 2013

Non-linear hysteresis is a complicated mechanical characteristic for magneto-rheological (MR) damper. In this paper, a new simple non-linear hysteretic model for MR damper is proposed to represent the hysteretic behavior. First, the force-displacement and force-velocity loops under a range of currents, amplitudes and frequencies are obtained by mechanical behavior test of a RD1097 type MR damper. Then the model's parameters are identified by the non-linear least square method from test data and fitted by the polynomials as functions of the supplied current. Finally, the accuracy and the effectiveness of the model are demonstrated by the RMS errors comparison between the reconstructed hysteretic curves and the experimental ones, and further are verified by seismic response reduction experiment under three excitations including the sinusoidal wave, the Pingsheng Bridge earthquake wave and the El-Centro wave. The results show that the proposed model has higher accuracy than some of existing models with explicit functions and is easier to be identified than those models with non-linear differential equations. Therefore, the proposed model can be effectively applied to simulation analysis in engineering control subjected to frequency-fixed or random excitations. © 2013 Elsevier Ltd.

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