Shen Y.,Hohai University |
Wang X.,Hohai University |
Wang X.,Jinan Rail Transit Group Co. |
Liu H.-L.,Hohai University |
And 4 more authors.
Journal of Mountain Science | Year: 2017
Soil behavior can reflect the characteristics of principal stress rotation under dynamic wave and traffic loads. Unequal amplitudes of tensile and compressive stresses applied to soils have complex effects on foundation soils in comparison with the pure principal stress rotation path. A series of undrained cyclic hollow torsional shear tests were performed on typical remolded soft clay from the Ilexi area of Nanjing, China. The main control parameters were the tensile and compressive stress amplitude ratio (α) and the cyclic dynamic stress ratio (η). It was found that the critical η tended to remain constant at 0.13, when the value of the compressive stress amplitude was higher than the tensile stress amplitude. However, the influence of the tensile stress was limited by the dynamic stress level when α= 1. For obvious structural change in the soil, the corresponding numbers of cyclic vibration cycles were found to be independent of α at low stress levels and were only related to η. Finally, a new method for evaluating the failure of remolded soft clay was presented. It considers the influence of the tensile and compressive stresses which caused by complex paths of the principal stress rotation. This criterion can distinguish stable, critical, and destructive states based on the pore-water-pressure-strain coupling curve while also providing a range of failure strain and vibration cycles. These results provide the theoretical support for systematic studies of principal stress rotation using constitu tive models. © 2017, Science Press, Institute of Mountain Hazards and Environment, CAS and Springer-Verlag Berlin Heidelberg.
Jiahai L.,Jinan Rail Transit Group Co. |
Guofu W.,Jinan Rail Transit Group Co. |
Linhai L.,Jinan Rail Transit Group Co.
Proceedings - 2016 International Conference on Smart City and Systems Engineering, ICSCSE 2016 | Year: 2016
U-Shaped beam is an open thin-walled section with low tensional rigidity, high installation precision and high construction difficulty. Under the construction requirements of the U-shaped beam of Jinan railway Line R1, the researcher designs a special lifting machine, selects a reasonable transport vehicle, and the hydraulic balance system of road transportation is designed at the same time to reduce the torsion and ensure the construction quality of the U-shaped beam structure. Good results have been achieved. © 2016 IEEE.
Lyu H.-M.,Shanghai JiaoTong University |
Wang G.-F.,Jinan Rail Transit Group Co. |
Wang G.-F.,Shandong University of Science and Technology |
Cheng W.-C.,Shanghai JiaoTong University |
Shen S.-L.,Shanghai JiaoTong University
Natural Hazards | Year: 2016
This paper reported a tornado hazard happened on June 23, 2016, in Yancheng city, Jiangsu Province. The moving footprint of this huge tornado was from west to east. Shuoji, Chenliang, Goudun, Banhu, Xingou, Wutan towns in Funing district and Sheyang town in Sheyang district were severely hit by this tornado. This tornado along with rainstorm and hailstorm had claimed 99 lives and caused more than 3800 flats to collapse as well as damaged 48 high-voltage circuits. As the cold air from northwest met the subtropical high pressure system that forms over relatively cool water bodies (i.e., Indian and Pacific Oceans), such a powerful meteorological phenomenon was initiated. The strong connective airflow intensified the development of this tornado. Based on the preliminary investigation and analysis of this tornado, cost-effective timber structures with adequate anchorage of the framing to foundations and adequate connection between walls and roofs may be recommended to ensure occupants safety and reduce potential damage in these extreme wind events. Additionally, it is suggested to utilize early warning system along with geographical information system (GIS), Global Positioning System (GPS), and remote sensing (RS) (3S) to monitor and precast the occurrence of rainfall, hailstorm, and tornado hazards in future. © 2016 Springer Science+Business Media Dordrecht
Wang G.,Shandong University of Science and Technology |
Wang G.,Jinan Rail Transit Group Co. |
Lu L.,Jinan Rail Transit Group Co. |
Sun J.,Shandong University of Science and Technology
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2015
In the tunneling of the Jinan rail transit line R1 passing under Lashan River, the stability of surrounding rock, the effect of shield thrust and the sensitivity of interface parameters were analyzed employing both the theoretical calculation and numerical method. The study showed that, as the shield passed through the medium interface, the settlement of surrounding rock at arch crown increased firstly and then decreased, while the principal stress in the lining segment increased firstly, then declined and rebounded. The interface effect reached 4 meters to the front and 10 meters in behind. If the safety factor was 2, the support stress ratios maintaining the stability of rock medium, soil medium and excavation face of watercourse were 0.24-2.80, 0.34-1.65, 0.54-1.40, respectively. The rock-soil interfacial effect was found to increase with the increase of stiffness ratio of medium and interface dipping angle. Especially in the situation of k≥4 and θ≥20°, the disturbance sensitivity of interface surrounding rock thrust became more significant. © 2015, Science Press. All right reserved.
Wang W.,Shandong University of Science and Technology |
Sun J.,Shandong University of Science and Technology |
Sun J.,Jinan Rail Transit Group Co Ltd |
Lu L.,Shandong University of Science and Technology |
Lu L.,BGI Engineering Consultants Ltd
Zhongguo Kuangye Daxue Xuebao/Journal of China University of Mining and Technology | Year: 2016
For overcoming the difficulty of in-situ stress testing caused by borehole collapse, softening and disintegration under water in weakly consolidated soft rock, an inversion analysis method of initial in-situ stress was proposed. On the basis of damped least square method, the improved displacement solutions of roof, floor and wall of straight wall-semicircle arch roadway were respectively established by introducing the geometric modified coefficients to revise the theoretical displacement solutions of circular roadway. The distribution of in-situ stress was determined according to the field displacement test data of roadway in Yili No.4, and forward verification for in-situ stress was carried out by numerical analysis. The results show that the improved displacement solution of roadway is highly fitted with the numerical simulation and field test data. The gravity stress is the dominant geostress in the testing mining area, and the maximum horizontal principal stress is 0.7~0.8 times the vertical stress. The direction of maximum horizontal stress dimension is N10°E~N20°E, which is important directional influence on drivage and arrangement of roadway. © 2016, China University of Mining and Technology. All right reserved.
Liu X.,Jinan Rail Transit Group Co. |
Xiang Z.,Tongji University |
Niu J.,Tongji University |
Xia K.,Tongji University |
And 3 more authors.
International Journal of Electrochemical Science | Year: 2015
The corrosion behaviors of amorphous, nanocrystalline and crystalline Ni-W alloys coating were systematically investigated by ultrasonic-assisted direct current electrodeposition. Through potentiodynamic polarization test and electrochemical impedance spectroscopy analysis, it was found the self-corrosion trend of nanocrystalline coating < crystalline coating < amorphous coating, whereas the anti-corrosion property trend of nanocrystalline coating > crystalline coating > amorphous coating in alkaline solution contrary to that in acid solution. The mechanism of corrosion resistance is amorphous homogenous structure and WO3 films in acid solution and coating high electrical resistance in alkaline solution corresponding to different structure, respectively.
Liu J.,Ocean University of China |
Liu J.,Jinan Rail Transit Group Co. |
Yu D.,Ocean University of China |
Wang G.,Jinan Rail Transit Group Co. |
Qin X.,Jinan Rail Transit Group Co.
Proceedings - 2015 International Conference on Intelligent Transportation, Big Data and Smart City, ICITBS 2015 | Year: 2015
Based on the comparison of experiment and field testing, we investigate the influence of the samples size on the concrete compressive strength with drilled core method. For this purpose a lot of core specimens having height-diameter ratios of 0.5, 0.7, 1.0, 1.2 and diameters of 50mm, 70mm, and 100mm were casted in concrete laboratory and in field. The relationship of concrete compressive strength between the different height-diameter ratios and the different diameters is determined. The modified relationship between the small diameter core sample and the concrete strength standard test block of bridge engineering is established. And the linear regression analyses exhibited better performance. © 2016 IEEE.
Wang G.-F.,Jinan Rail Transit Group Co. |
Yang P.-S.,Jinan Rail Transit Group Co. |
Liu H.-D.,Jinan Rail Transit Group Co.
Journal of Railway Engineering Society | Year: 2016
Research purposes: Train is the direct carrier of passangers in urban rail transit, and train marshalling form involves the urban planning, passenger flow, train operation, line network resource sharing, and so on. From the perspectives of urban rail transit line characteristics, traffic volume forecasting, vehicle capacity, transport capacity matching, line network resource sharing, dynamic ratio of motor cars and trailers and economy, the optimal Jinan rail R1 line train marshalling was determined through the break-even analysis. Research conclusions: (1) Considering various factors, 4-4-6 marshalling is recommended for Jinan rail transit R1 in the early, the near future and the far future stages. The ratio of motor cars and trailers is 3:1 in the early and the near future, 4:2 in the far future. (2) Passenger flow prediction is the main factor affecting vehicle type and train marshalling selection, depending on urban planning and development. (3) According to the breakeven analysis, train expansion after 10 years of operation is a more economical solution. (4) The results have been applied on the design of Jinan rail transit R1, and can provide a reference for the similar projects. © 2016, Editorial Department of Journal of Railway Engineering Society. All right reserved.
Zhang R.,Jinan Rail Transit Group Co. |
Zhao J.,Dalian University |
Wang G.,Dalian University
Mathematical Problems in Engineering | Year: 2016
Under the condition of the plane strain, finite element limit equilibrium method is used to study some key problems of stability analysis for anchored slope. The definition of safe factor in slices method is generalized into FEM. The "true" stress field in the whole structure can be obtained by elastic-plastic finite element analysis. Then, the optimal search for the most dangerous sliding surface with Hooke-Jeeves optimized searching method is introduced. Three cases of stability analysis of natural slope, anchored slope with seepage, and excavation anchored slope are conducted. The differences in safety factor quantity, shape and location of slip surface, anchoring effect among slices method, finite element strength reduction method (SRM), and finite element limit equilibrium method are comparatively analyzed. The results show that the safety factor given by the FEM is greater and the unfavorable slip surface is deeper than that by the slice method. The finite element limit equilibrium method has high calculation accuracy, and to some extent the slice method underestimates the effect of anchor, and the effect of anchor is overrated in the SRM. © 2016 Rui Zhang et al.
Li Y.,Shandong University |
Zhou H.,Shandong University |
Zhou H.,Jinan Rail Transit Group Co. |
Zhang L.,Huazhong University of Science and Technology |
And 3 more authors.
Construction and Building Materials | Year: 2016
The reinforcement for jointed rock mass using rock bolts has always been one of the most effective and economical geo-structural reinforcing technologies widely used in practical civil engineer projects for a long time. In the field of rock mass engineering, the reinforcement effect of the rock bolt(s) on rock mass is much more obvious due to a large number of natural fractures in rock masses. In this paper, an optimized method using Discontinuous Deformation Analysis for Rock Failure (DDARF) is presented to perform numerical investigations on mechanical property and reinforcement effect of bolted jointed rock mass. In order to verify the effectiveness of the proposed optimized DDARF, laboratory experiments using analog material have also been performed. Experimental results are very favorable with those obtained by the optimized DDARF. Moreover, this numerical method has also been employed to study mechanical property and reinforcement effect of rock specimen with single joint and single rock bolt when the joint and rock bolt have different locations in the specimens. The optimal reinforced location for the rock bolt in the specimen has been obtained through the comparative analysis of reinforcement effects under different conditions. The single jointed rock specimens with two rock bolts have also been numerically simulated and the optimal reinforcing location for the rock bolts has also been obtained. It is concluded that this optimized DDARF would provide an alternative effective tool to investigate the mechanical property and reinforcement effect for bolted jointed rock mass. © 2016 Elsevier Ltd