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Zhao B.-J.,Chang'an University | Zhao B.-J.,Shaanxi Provincial Communication Construction Group | Zhu G.-R.,Shaanxi Provincial Communication Construction Group | Yin L.,Shaanxi Provincial Communication Construction Group
Applied Mechanics and Materials | Year: 2014

In order to study the stress of box-girder web under prestressing, and confirming the internal stress distribution of the web, analyzing of vertical prestressed box girder, curved beam prestressed sensitivity under the webs. Establishing finite element model of the box-girder webs vertical prestressing effect is analyzed, results show that the principal tensile stress of the web is sensitive to the vertical prestress, applying the vertical prestress can effectively reduce the principal tensile stress of the web; with the decrease of the effective vertical prestress, the neutral axis above the principal compressive stress decreases rapidly, while below the neutral axis decreases relatively slow; Under the same vertical preloading stress level, the roots of cross section of the compressive stress of web reserves than L/4 section of the web. © (2014) Trans Tech Publications, Switzerland.

Zhou Z.-J.,Chang'an University | Lu D.-W.,Chang'an University | Song W.,Shaanxi Provincial Communication Construction Group | Liang H.,Chang'an University | Ye W.-J.,Xi'an University of Science and Technology
Zhongguo Gonglu Xuebao/China Journal of Highway and Transport | Year: 2013

In order to find out the change rules of loess characteristics after freeze-thaw circle, Q2 loess samples with different moisture contents were prepared by moistening method. After freeze-thaw circle under different test temperatures and without water supply, tests of liquid and plastic limit, uniaxial consolidation and direct shear were conducted, and the relationships between physical and mechanical indexes of loess and moisture content and temperature were obtained. The results show that plastic index of samples after freeze-thaw circle with natural moisture content increases slightly with the decrease of temperature, compression modulus and shear strength decrease with the increase of moisture content; temperature influence on mechanical property of loess depends on the moisture content of samples, compression modulus decreases with the decrease of temperature, and the decreasing range changes with sample saturation in approximate quadratic function; when moisture content is less than critical value, cohesive force increases with the decrease of temperature, while cohesive force decreases when moisture content is more than critical value; internal friction angles of samples increase with the decrease of temperature, and the increasing range of internal friction angle increases with the increase of moisture content.

Weng X.-L.,Chang'an University | Zhang C.,Henan Zhongyuan Expressway Co. | Li C.-L.,Shaanxi Provincial Communication Construction Group | Shang S.-P.,Chang'an University | Li H.-Y.,Chang'an University
Zhongguo Gonglu Xuebao/China Journal of Highway and Transport | Year: 2013

In order to clearly describe the additional deformation of pavement layers between the old and new subgrade with differential settlement, a full scale model test was carried out to study the strain response of asphalt concrete pavement layer using a large subgrade differential settlement platform. The results indicate that the entire pavement is in tension under the foundation differential settlement and the lower layer is more affected; plastic deformation will develop in surface layer when the differential settlement reaches 14 cm; geogrid in old and new subgrade can alleviate the lower foundation differential settlement and increase the additional deformation of the pavement; to some extent, the vehicle load can alleviate the additional deformation due to the differential settlement; upon the occurrence of hollows under the pavement, deformation will be reflected in the asphalt pavement layers in the form of crown under the action of gravity.

Wang Z.-W.,Changsha University | Chen X.-L.,Changsha University | Li C.-L.,Shaanxi Provincial Communication Construction Group
Zhongguo Gonglu Xuebao/China Journal of Highway and Transport | Year: 2015

To provide reference for management and control of cascading failure behavior for road traffic network, the method to identify and sort influence sources of cascading failure was analyzed according to road traffic complex network characteristics. The load-capacity model was improved to describe cascading failure behavior of road traffic network, where the ratio of the failure sections was used to depict the degree of damage. Based on the method of comparative analysis, the recognition algorithm was devised to distinguish the importance of influence source in accordance with the change degree of the failure consequence. Based on orthogonal experiment method, the procedure was built to sort the importance of influence sources in the light of range value. The results show that reserve capacity coefficient, travel network topology, travel total demands, route choice behavior, and attack mode are all important influence sources of cascading failure, and the importance sequence from big to small is attack mode, travel total demands, reserve capacity coefficient, travel network topology, and route choice behavior. ©, 2015, Xi'an Highway University. All right reserved.

Wang T.,Chang'an University | Wang T.,Northwest University, China | Yang R.,Chang'an University | Li A.,Northwest University, China | And 2 more authors.
Chemical Engineering Transactions | Year: 2016

In order to study the effects of Sasobit on rubber asphalt, performance tests of rubber asphalt before and after Sasobit adding and tests of different Sasobit adding processes were operated. The influences of Sasobit on the performance of rubber asphalt, effects of Sasobit adding process on Sasobit rubber asphalt were acquired. The results showed that: Sasobit makes the high temperature viscosity and low temperature ductility of rubber asphalt decrease, and the softening point increase, which are favourable to the workability and high temperature stability, and disadvantageous to the low temperature ductility of rubber asphalt; the preparation process of Sasobit rubber asphalt by adding Sasobit into the finished rubber asphalt is better. Copyright © 2016, AIDIC Servizi S.r.l.

Li N.,Chinese Research Institute of Highway | Zhang D.-S.,Shaanxi Provincial Communication Construction Group | Han W.-W.,Chinese Research Institute of Highway | Shen A.-Q.,Chang'an University
Advanced Materials Research | Year: 2014

To study the effect of different dosage of recycled asphalt mixture particles on the performance of concrete, the mechanical characteristics, shrinkage performance and durability testing were performed, the results show that the compressive strength and flexural strength of concrete are decreased with the increase of dosage recycled asphalt mixture particles, while still meet the regulatory requirements; the capability of plastic shrinkage resistance can be improved by incorporated recycled asphalt mixture fine particles, yet slight effective on the temperature shrinkage; the durability of concrete changes as a result of incorporation of recycled asphalt mixture fine particles, the durability of concrete with a dosage of 20% is considered in the optimal state, so the recommended dosage is 20%. © (2014) Trans Tech Publications, Switzerland.

Hu D.,Chang'an University | Qu T.,Chang'an University | Wang H.,Shaanxi Provincial Communication Construction Group | Chen L.,Chang'an University
Applied Mechanics and Materials | Year: 2013

There are few researches on seismic response of reinforced concrete rib arch bridges at present; therefore, it is necessary to analyze seismic performance of this kind of bridges. Based on the engineering background of a three-span reinforced concrete rib arch bridge, a full bridge finite element model is built to analyze the structural dynamic characteristic and seismic response of the bridge. The internal forces and displacements of each key section is compared and discussed when the bridge is excited by horizontal unidirectional ground motion or the combination of vertical and horizontal ground motion. The structural seismic response calculated with different analysis methods is compared. The research results of this study can be used as a reference for the seismic design of similar bridges. © (2013) Trans Tech Publications, Switzerland.

Meng J.,Chang'an University | Meng J.,Shaanxi Provincial Highway Survey and Design Institute | Zhao B.-J.,Chang'an University | Zhao B.-J.,Shaanxi Provincial Communication Construction Group | Liu J.-M.,Shaanxi Provincial Highway Survey and Design Institute
Chang'an Daxue Xuebao (Ziran Kexue Ban)/Journal of Chang'an University (Natural Science Edition) | Year: 2013

In order to forecast the influence of concrete shrinkage and creep on the performance of structures, the CEB-FIP model, ACI model, BP model and GL-2000 model were adopted respectively to calculate and analyze the shrinkage and creep of concrete and the results acquired with various calculating methods were compared under identical conditions. The results show that the theoretical thickness of structures is very sensitive to shrinkage and creep of concrete, but the creep coefficient is not sensitive to theoretical thickness of structures; the creep effect of concrete decreases with the increase of loading period; when loading period increases from 3 days to 28 days, the final value of concrete creep effect is reduced by about 80%; shrinkage and creep effect are very sensitive to average relative humidity of environment, when the average relative humidity of environment is enhanced from 50% to 80%, the creep effect is reduced by approximately 30%, while the shrinkage effect is reduced by as much as 50%; comparatively, the change of environmental relative humidity imposes greater influence on shrinkage effect than on creep effect of concrete.

Zhang L.-Y.,Chang'an University | Liu L.-J.,Chang'an University | Yang L.-F.,Shaanxi Provincial Communication Construction Group
Zhongguo Gonglu Xuebao/China Journal of Highway and Transport | Year: 2010

In order to determine initial cable forces of large curvature cable-stayed bridge with full framing cast-in-place under constant load, authors used the bending, torsion, tension and compression strain energy of main girder and cable-tower as objective function. Considered constraint condition, such as displacement, bending moment, cable force, finite element model was used to define internal force and to get displacement influence matrix, objective function was solved and initial cable force was got based on active set method in MATLAB. Application result of test bridge indicates that this method which can be used in large curvature cable-stayed bridge with full framing cast-in-place is simple and convenient. It is also easy to be generalized. The precision calculated by the method satisfies engineering requirements.

Zheng M.,Chang'an University | Han L.,Chang'an University | Wang F.,Qinghai Airport Co. | Mi H.,Xian Highway Institute | And 2 more authors.
Construction and Building Materials | Year: 2015

The objective of this study is to develop applicable solar heat reflective coating for asphalt pavement. The cooling effects of 10 self devised coats as well as a Japanese paint were compared and evaluated based on laboratory and field tests. Ceramic particles and machine made sands were applied to enhance coat anti skid performance. Results show that scheme 8, 9 and 10 performed better indoor cooling effect than others with a cut in specimen surface temperature by 30°C. While scheme 5 excelled others at outdoor effect by 10°C. In addition, the variation of cooling effect with time between different schemes in field test was similar to that in the laboratory although the outdoor effect of each coat was poorer than the indoor effect. The anti-skid experiment suggested that spreading 160g/m2 of 1.18mm machine made sands contributed to the greatest increase in the British Pendulum Number (BPN). Finally, three optimum schemes were recommended for practical application according to their outdoor cooling effect and impact on driving glare. © 2015 Elsevier Ltd.

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