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Zhang W.-J.,Tianjin University | Jin M.-M.,Tianjin University | Su R.,Tianjin University | Zhang G.-L.,Tianjin University | And 2 more authors.
Zhongguo Gonglu Xuebao/China Journal of Highway and Transport | Year: 2016

Targeting at the mechanical properties of steel and concrete composite segment for shield tunnel, 4 groups of model tests on steel and concrete composite segment under pure bending loading were added on the basis of existing 10 groups of tests and previous research results. The impacts of the thickness change of steel plates, headed shear studs and joint plates on the carrying capacity and deflection of composite segment were further studied, and the results from the new tests were compared with those existing results. Meanwhile, according to previous researches, a bilinear method was proposed to determine the yield load of composite segment. The results show that a) the thickness of skin plate has the most significant impact on the deflection and carrying capacity of composite segment; b) shear studs can effectively restrict the deformation of composite segment and improve its carrying capacity; c) joint plates acting as shear studs markedly improve the carrying capacity of composite segment without shear studs but don't affect the carrying capacity of which with shear studs. Finally, from the perspective of the newly added influencing factors on mechanical properties, the strain distribution laws along width and height direction of the composite segment in new tests and existing tests were analyzed and replenished. The testing results of the 14 groups give a comprehensive insight into the mechanism of steel and concrete composite segment for shield tunnel. © 2016, Editorial Department of China Journal of Highway and Transport. All right reserved.


Yang H.-J.,China Railway Sixth Group Co. | Kong H.,Beijing Municipal Construction Co.
Journal of Railway Engineering Society | Year: 2015

Research purposes: During the excavating of large-span subway station with shallow cover, the phenomenons such as repeated disturbance, complex mechanical conversion easily occur, which bring excessive surface subsidence. In the paper, the construction of tunnel arch excavation and support with shallow cover is introduced mainly, the analysis of deformation law, and influences of construction sequence are made on basis of monitoring and measurement for the surface subsidence. Research conclusions: The research conclusions show: (1) The average value of surface subsidence is up to -36.31 mm, the limit of the surface settlement should be modified in order to decrease both negative effect on the surrounding environment and construction cost. (2) The ground surface settlement trough due to the construction is at the center of subway station, the distance between flex point and the center of subway station is about 18 m, meanwhile, the surface subsidence over 20 m from the center of subway station decreases rapidly, the distribution of the surface subsidence is 25~30 m from both sides of the subway station. (3) The surface subsidence due to construction of the subway station mainly occurs in a small pilot tunnel excavation supporting and buckle arch construction stage, 48.47% and 93.03% of the total settlement, especially during the course of a small pilot tunnel excavation supporting, which is close to half of the total settlement. (4) The result can provide the reference for design and construction of the similar engineering. ©, 2015, Editorial Department of Journal of Railway Engineering Society. All right reserved.


Guo C.,Beijing Jiaotong University | Guo C.,Beijing No.4 Municipal Construction Engineering Co. | Kong H.,Beijing Municipal Construction Co. | Wang M.,Beijing Jiaotong University
Tumu Gongcheng Xuebao/China Civil Engineering Journal | Year: 2015

Excavation of EPB (Earth Pressure Balance) shield in sand and cobble strata is often accompanied by some problems, that is, unusual increase of shield thrust and cutterhead torque and serious wear of screw conveyor, cutterhead, and cutter bits. Mucking improvement is an effective means to solve the problem above. Therefore, the in-situ tests of mucking improvement are performed and the workability performance of mucking improved by bentonite and foam additive is analyzed based on shield tunneling project of Beijing Subway Line 9 in sand and cobble strata. The results show that the thrust forces, torque and mucking temperature have been reduced greatly using the mucking improved by bentonite and foam additive; the shield safety under stopped state has been improved effectively since the filter cake has fine properties to maintain the pressure at excavation face. ©, 2015, Editorial Office of China Civil Engineering Journal. All right reserved.


Zhang W.,Tianjin University | Jin M.,Tianjin University | Zhang G.,Tianjin University | Guo C.,Beijing No.4 Municipal Construction Engineering Co. | Kong H.,Beijing Municipal Construction Co.
Tumu Gongcheng Xuebao/China Civil Engineering Journal | Year: 2015

The settlement distribution of double-tube single-track shield tunnels is different from that of single-tube single track shield tunnel because of the interactions between the double tube tunnels. Meanwhile, the distribution and magnitude of effective stress in stratum are changed when the double-tube single-track shield tunnels passing under a lake, which can also lead different settlements to the overlaying soil of tunnels. Based on the stiffness equivalent method and the analytical solution proposed by Verrujit and Booker, a new calculation equation is derived to calculate the stratum settlements when double-tube single-track shield tunnels passing under a lake. Combined with the project of section between ZAO YING station and DONG FENG BEI QIAO station of Beijing Metro Line 14, layered the settlements are calculated using the new equation. It shows that the analytical results agree with the site monitoring results. This proves the rationality and applicability of the proposed equation. ©, 2015, Editorial Office of China Civil Engineering Journal. All right reserved.


Wang B.,Beijing Jiaotong University | Wang B.,Beijing Municipal Construction Co. | Kong H.,Beijing Municipal Construction Co. | Zhang W.,Tianjin University | And 3 more authors.
Tumu Gongcheng Xuebao/China Civil Engineering Journal | Year: 2015

Water-saturated stratum of sandy gravel clay beneath the lakes has the characteristics of high hydraulic pressure, high water permeability, unblocked ground water flow, quick ground water recharge, poor self-stability and large size cobble boulder. The constructions of long distance and small radius curve will meet the following risks when the shield machines pass beneath the lakes with no closure: complicated arrangements of conventional monitoring points; removing problem of large size cobble boulder; severe wear of cutterhead and cutter bits; shield machine stuck and segments damaged; crack and propagation of the induced settlement and heave of plastic zones by ground disturbance; difficultly in changing or repairing the cutterhead and cutter bits during shield machine stop. In this paper, taking the following project as an example, the shield tunnels pass beneath the North Lake and South Lake of Chaoyang Park for Beijing Subway Line 14. Firstly, the outer diameter of shield machine, aperture ratio of cutterhead, wear of cutter bits, torque of cutterhead, and volume of muck spoil etc. are calculated and verified. Secondly, the proposed rational excavation parameters and control technologies are used in the project of EPB shield of spoke cutterhead long-distance passing beneath lake in water-saturated stratum of sandy gravel clay. The two monitoring systems of ground and underground ensure the safety of the shield excavation. Finally, it is shown that the EPB shield of spoke cutterhead can be used in the water-saturated stratum of sandy gravel clay. ©, 2015, Editorial Office of China Civil Engineering Journal. All right reserved.

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