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Gu T.-F.,Northwest University, China | Gu T.-F.,ZhongJiaoTongli Construction Co. | Wang J.-D.,Northwest University, China | Wang N.-Q.,Xi'an University of Science and Technology
Yantu Lixue/Rock and Soil Mechanics | Year: 2013

The Lüliang airport landslide is a large loess landslide which was found in early construction of the airport. Due to airfield runway next to the northeastern of the landslide, the landslide makes a large influence on the engineering construction and safe operation. In order to assess landslide risk and prevent its damage, the geological features and formation mechanism of the landslide are analyzed based on the detailed engineering geological investigation and testing work. The landslide is considered as a multilayer landslide developed in loess layer. There are three steps on the landslide; and the main sliding surface locates in the paleosol layer of Lishi loess. Three-dimensional geological model is established using GIS; and the stability of the landslide is evaluated by limit equilibrium method and shear strength reduction method. Results from three-dimensional limit equilibrium analyses show that most parts of the landslide are stable or basic stable in natural state. From strength reduction analysis, the safety factor of the whole slope is 1.26. It is shown that the most dangerous areas appear in the posterior margin of landslide II and landslide I-3. In case of loading or rainfall condition, it is likely to slide again. In conclusion, three-dimensional stability analysis can more truly reflect the actual state of landslides, especially for complex landslide.

Zheng M.-L.,Chang'an University | He L.-T.,China Communications Construction Company Ltd. | Gao X.,ZhongJiaoTongli Construction Co. | Wang F.,Chang'an University | Cheng C.,Southwest forestry University
Jiaotong Yunshu Gongcheng Xuebao/Journal of Traffic and Transportation Engineering | Year: 2013

In order to improve asphalt pavement high temperature stability in summer and mitigate urban heat island effect, a new type of heat-reflective coating was applyed on the surface of asphalt pavement. The working principle of heat-reflective coating was analyzed, the thermal-physical environment performance comprehensive test device of heat-reflective asphalt pavement was developed, and the cooling effects of asphalt mixtures with different color coatings were studied by using the device. The skid resistance performances of coatings with different thicknesses were evaluated based on pendulum type friction coefficient measuring instrument. Analysis result shows that the cooling effect of white heat-reflective coating is better than grey coating, white heat-reflective coating on specimen can cool 18°C-25°C within door test, the temperature of 2.5 cm place inside specimen reduces by 9.4°C, and the temperature of grey coating surface reduces by 12°C. The cooling ability of heat-reflective coating increases with the increase of coating thickness, but it will tend to be constant while reaching certain thickness. The sensible dosage of heat-reflective coating is 0.6 kg·m-2 comprehensively considering cooling effect and cost. With the increase of coating thickness, the surface skid resistance performance of pavement reduces, and it is recommended to spread antiskid particles in the coating to meet traffic safety requirements.

Li H.-Q.,Inner Mongolia University | Yang W.-L.,China Academy of Transportation science | Gao X.,ZhongJiaoTongli Construction Co.
Zhongguo Gonglu Xuebao/China Journal of Highway and Transport | Year: 2013

In order to overcome the calculation misconvergence in the analysis of large complicated structure's ultimate bearing capacity with solid element model, the wires and bars in pre-stressed structures were meshed as blocks in the element, and the concrete was simulated with solid degenerated shell element. In the analysis, perfect elasto-plastic model was adopted for reinforced bars and pre-stressed wires, while for concrete, the Ohtani-Chen multiple strengthening model was applied. Meanwhile, the Total Lagrange method was applied to calculate the geometrical nonlinearity effect, and the orthotropic crack model was applied to simulate the concrete cracks. The analysis theory was used to simulate the loading and failure process of a simple hollow board beam, which showed fair accordance with the test results. Then the bearing capacity of a typical 5 span pre-stressed concrete frame bridge with high piers was calculated and analyzed with both the geometrical nonlinearity and material nonlinearity effect considered. The calculation results were compared with that with ABAQUS. The results show that the proposed method can overcome the misconvergence in the calculation induced by the concrete cracks and the real collapse state of the structure can be derived.

Li H.-Q.,Inner Mongolia University | Gao X.,ZhongJiaoTongli Construction Co. | Yang J.-G.,CAS Lanzhou Cold and Arid Regions Environmental and Engineering Research Institute | Yang J.-G.,China Academy of Transportation science
Chang'an Daxue Xuebao (Ziran Kexue Ban)/Journal of Chang'an University (Natural Science Edition) | Year: 2013

In order to know about permeability of asphalt concrete pavement during early stage and find the recessive disease, permeability test in the laboratory was improved. AC-20 and AM-20 were used to make rut test piece with air voids of 4%, 6%, 8%, 10%, 12% and 14% respectively. Based on permeation and illumination test by using iodine-tungsten lamp, correlation between volume of air voids and permeability, temperature of road surface and permeability were studied. Besides, the correlation was verified by application. The result showed that air voids of asphalt mixture is one of the main factors contributing to road surface temperature in the fine day after rain except solar radiation, aggregate lithological characters, environment and other natural factors. Permeability coefficient shows linear increase with air voids of rut test piece and increases dramatically when air void is larger than 9%; after illumination by iodine-tungsten lamps, difference in temperature of rust test piece increases firstly, then decreases and tends to zero lastly with illumination time. This paper can provide reference for recessive study of asphalt concrete pavement, and basis for time decision-making of preventive maintenance.

Zhang H.,Shenyang Jianzhu University | Fang S.,Shenyang Jianzhu University | Yin H.,ZhongJiaoTongli Construction Co.
Advanced Materials Research | Year: 2012

For the purpose of providing useful reference for optimizing the design of Collision-Prevention Device of Bridge Pier, analyzing the collision parameters and putting forward the ideal size of the circular steel tube and angle steel in absorbing energy, the ship impacting the steel tubular truss, which belongs to the Collision-Prevention Device of Bridge Pier, is simulated. The water level of ship and the size of circular steel tube and angle steel are discussed respectively with the ANSYS/LS-DYNA program, which is the nonlinear dynamic analysis software, to study the impact of change of the single collision parameter to the equipment for anti-collision which is the steel tubular truss.when the ship impacts the steel tubular truss under the ideal level, the circular steel tube and the angle steel could play fully in resisting the collision of ship, achieved a better absorbing effect. The circular steel tube can play a chief absorption effect through the bending deformation, while the relatively small energy is absorbed by the angle steel through the buckling deformation. The best sizes selected through the optimum structural design are shown as follows: the diameter of circular steel tube is 800mm; the thickness of tubular wall is 12mm; the size of angle steel is 100mm×100mm×12mm.

Feng Z.-J.,Chang'an University | Wang H.,Shaanxi Expressway Construction Group Company | Wei J.,Chang'an University | Gao X.,Zhongjiaotongli Construction Co. | And 2 more authors.
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2015

In order to ascertain the effect of loess gulch on the bearing capacity of bridge pile foundation, for the first time, based on the self-developed platform model test, the model tests can fully reflect the characteristics and work performance of pile foundation in loess gulch area. The change rules of vertical bearing capacity, pile axial force and lateral friction force of the pile foundation with different slopes and pile lengths are analyzed, and some engineering technical advices are given based on test results. The results show that: (1) With the increase of slope, the bearing capacity of piles with the same pile length decreases, the influence degree of bearing capacity increases gradually, and the range varies from 7% to 35%. (2) The pile bearing capacity increases with the increase of pile length to some extent; when the pile length increases to a certain length, the rate of increase becomes slow. (3) The effective pile length with the same buried depth decreases with the increase of slope. (4) The design of bridge pile foundation should fully consider the engineering technology of preventing the soil around piles being eroded in the loess gulch area. © 2015, Editorial Office of Chinese Journal of Geotechnical Engineering. All right reserved.

Feng Z.-X.,Hefei University of Technology | Yuan H.-Z.,Chang'an University | Liu J.,Anhui University of Architecture | Gao X.,Zhongjiaotongli Construction Co. | Zhang W.-H.,Hefei University of Technology
Journal of Central South University | Year: 2013

Referring to the 1 248 survey data of rural population in 14 provinces of China, the influencing factors of trip time choice were analyzed. Based on the basic theory of disaggregate model and its modelling method, nine grades were selected as the alternatives of trip time, the variables affecting time choice and the method getting their values were determined, and a multinomial logit (MNL) model was developed. Another 1 200 trip data of rural population were selected to testify the model's validity. The result shows that the maximum absolute error of each period between calculated value and statistic is 3.6%, so MNL model has high calculation accuracy. © 2013 Central South University Press and Springer-Verlag Berlin Heidelberg.

Pu G.-N.,Chang'an University | Pu G.-N.,ZhongJiaoTongli Construction Co Ltd | Zhao Y.,Chang'an University | Song Y.-F.,Chang'an University
Chang'an Daxue Xuebao (Ziran Kexue Ban)/Journal of Chang'an University (Natural Science Edition) | Year: 2012

In order to study the mechanical properties of hollow slab bridges before and after strengthening and verify the strengthening effect, based on a practical example of a 30 m span prestressed hollow slab bridge, the variation and discipline of the main mechanical properties of a hollow slab bridge before and after strengthening with beam-reduction and rib-addition method were discussed through the analysis and comparison of the data from static test before and after strengthening. The results show that the test cross-sectional stress and deflection of the hollow slab bridge after strengthening with beam-reduction and rib-addition method are greatly decreased and the transverse distribution tends to be uniform comparison of strain and deflection measured values before and after strengthening reflects that after strengthening bridge test section measured strain value is 27% to 83% of that before strengthening, measured deflection value after strengthening is 28% to 45% of that before strengthening, and the stress and deflection are reduced significantly, which indicates that the old beam plate stress state is improved apparently and the carrying capacity is improved effectively after strengthening and the strengthening effect is obvious.

Ren W.-F.,Central South University | Ren W.-F.,China Communications Construction Company Ltd. | Gao X.,ZhongJiaoTongli Construction Co. | Wang X.-H.,Central South University | Tu P.,Central South University
Jiaotong Yunshu Gongcheng Xuebao/Journal of Traffic and Transportation Engineering | Year: 2013

Undisturbed soil was drilled for soil test by using geological drilling rig above the tunnel center line. The settlements of tunnel surface and vault were measured by using electronic level. Tunnel horizontal convergence values were measured with JSS30A digital convergence instrument. Pressures among surrounding rock and initial support, initial support and secondary lining were measured with JTM-V2000D vibrating wire pressure gauge. The surrounding rock deformation and pressure of Zhaizigang Tunnel were measured, the surrounding rock deformation rule and mechanical characteristic of tunnel in water-rich full-weathering granite area were got. Analysis result shows that the dividing line of deep and shallow submersion tunnels is 2 times tunnel diameter. Vertical displacement and horizontal displacement appear simultaneously in tunnel entrance. The horizontal convergence stability time of surrounding rock and settlement stability time of vault have little relationship with tunnel depth. The horizontal convergence value and vault settlement increase with the increase of shallow submersion tunnel depth, but they have little relationship with the depth of deep submersion tunnel. Pressures are evenly distributed between surrounding rock and initial support, pressure difference among measurement points of shallow submersion tunnel is little, pressure gradually increases with the increase of tunnel depth. The uneven degree of pressure distribution increases for deep submersion tunnel, pressure value changes very little with the increase of tunnel depth.The pressure between surrounding rock and initial support is greater than that between initial support and secondary lining, the maximum pressure between initial support and secondary lining is not greater than 100 kPa.

Sun Z.,Yantai University | Mao Y.,ZhongJiaoTongli Construction Co. | Liu J.,Yantai University | Zhao Q.,Yantai University | Chu M.,Yantai University
Open Civil Engineering Journal | Year: 2015

Assembled shear wall built with precast two-way hollow slab is a new-typed shear wall built with precast concrete. In order to study its mechanical property, a quasi-static experiment is conducted with 1 reinforced concrete shear wall and 2 new type shear walls as the study objects. It was found that the internal and vertical joints of the wall body were vulnerable parts so that the new-typed shear wall experienced the loading process from the whole wall to the portioned wall. So, brittle shear failure can be avoided, deformability and anti-collapse performance are greatly improved, and shear capacity of wall body is reduced. The new-typed shear wall is reasonably structured, with convenient and reliable horizontal and vertical reinforcement, which leads to satisfactory vertical joint force-bearing capacity. Thus, it can be applied in practical construction © Sun et al.; Licensee Bentham Open

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