Papers by Author: Xin Jiang Wei

Abstract: The construction method for immerse tube tunnelling varies significantly in sites with different hydrogeological conditions. Using the construction process of the undersea immerse tunnel at Shenjiamen harbour, Zhoushan city, Zhejiang Province as an example, the overall construction process of undocking, float transporting, immerse positioning, locking, grouting and backfilling were introduced in this study, with possible problems at each stage listed in details. The problems occurred when grouting Tube E1, E2 and E3 (floating or settling) and relevant solutions were concluded and the related possible causes were analysed.

Abstract: Urban tunnels mainly include subway tunnels, street-passage tunnels and underground road tunnels etc. With the development and utilization of underground space, urban tunnels have developed rapidly in recent years. At the same time, development of urban tunnels faces new opportunities. However, related professionals are not sufficient to make it come true. This thesis discusses feasibility of establishing ‘Urban Tunnels’ in the major Civil Engineering, including employment situation of Civil Engineering, integration with the demands of Zhejiang Province and Hangzhou City, misplaced development with other colleges and universities and the features of students majoring in civil engineering. Besides, it makes sufficient preparation in aspects of hardware, software, teachers and social support, which makes the construction of new major be implemented successfully according to plans and steps.

Abstract: Moisture transportation is a key factor to affect the long-term safety of underwater concrete tunnel. According to the inside and outside environment of tunnel, the moisture transportation equation in unsaturated concrete of underwater tunnel was raised. Finite difference method was adopted to solve the nonlinear partial differential equation of moisture diffusion. The study shows that the changes of water saturation in concrete are mainly concentrated in the surface of tunnel wall and amplitude is gradually slowing down over time. Saturation changes greater in the outside than inside. The wetting state is more obvious than drying state.

Abstract: The settlement of immersed tube tunnel may be influenced by variety factors in construction, operation and loads. The factors causing the immersed tube tunnel settlement were summarized and described in-depth by cases and data. Combined the mechanism analysis with the construction process, the action time of different loads along the construction process is summarized, the consolidation characteristics and settlement mechanism of original state soil layer and base layer are analyzed. The mechanisms and variations of tidal loading, siltation and dredging disturbance, groundwater level drawdown are elaborated.

Abstract: The long-term uneven settlement may cause the pipe structure cracking, leakage or even serious damage during the operation of the immersed tunnel. Settlement control measures of immersed tunnel were generalized from design-construction-operation three stages as the time order, and the control measures in the construction stage was particular emphasized. The treatment methods of the base layer were reclassified into compact the base, replace the base and pile base three types and relative project cases were enumerated. Contrary to the shortage of present stage, control measures and suggestion that fit soft base were raised after compare.

Abstract: Considering the interaction of building-soil-tunnel, the grillage beams foundation frame building vertical crossed by Double-O-Tube (DOT) shield tunnel was simulated by 3D MIDAS/ GTS software, and the impact of construction on the building was analyzed. The results show that: the ground settlement trough caused by DOT shield tunnel can be fitted by peck formula; during the passage of the shield tunneling through the building, the settlement of the building increased and settlement trough was wilder; the settlement was stable and had a little rebound when shield machine already passed the building; with the increase of driving distance, the first principal stress P1 increased and then was stable; with the increase of L, the shape of foundation settlement curve changed, and the maximum differential settlement between columns increased but was small.

Abstract: Excess pore water pressure caused by construction dissipated, resulting in consolidation settlement. The formula of initial excess pore water pressure around tunnel lining was deduced by stress relief theory, and its formula within the region of its distribution at any point was subsequently deduced by stress transfer theory. By comparing the measured data, shows that the calculated closed to the measured, and with the distance increased the initial excess pore water pressure decreased in a concave curve shape. When the depth of tunnel increased or the diameter decreased, would made initial excess pore water pressure between the tunnel bottom and tunnel center horizon around tunnel lining more different. At a certain depth, the mast initial excess pore water pressure above tunnel axis, away from the axis reduced; showing a similar PECK shape.

Abstract: The causes of water inflow and sand bursting on starting shaft disaster in shield tunnel were analyzed. The analytical model that groundwater seepage from substratum of the reinforced soil to gap in shaft wall on starting shaft in shield tunnelling was established. Using the semi-confined aquifer seepage theory, a practical calculation example was given. The result shows: under the assumption that the reinforced soil was complete exclusion of water, the accidents of water inflow and sand bursting in portal part were influenced by many factors including the length of reinforced soil, groundwater level and so on. The cost and safety of starting shaft engineering had positive correlation with the length of reinforced soil. Lowering the groundwater can significantly reduce water inflow disaster. Comprehensively considered factors of safety, economy, construction period and so on, the reasonable construction parameters can be determined.

Abstract: Three-dimensional (3D) analytical solution of soil deformation induced by ground loss in shield tunnelling construction was researched. It is put forward that the ground loss ratio is not a fixed value, but changes in driving direction. The calculation formula of ground loss ratio in driving direction was deduced. Based on two-dimensional (2D) analytical solution of uniform ground movement model of shield tunnelling, the three-dimensional analytical solution of ground deformation induced by ground loss is deduced. The settlement in vertical direction and the displacement in lateral horizontal direction at any point can be calculated; and the method is only applied to the construction phase. In analytical calculation: the predicted soil displacements are in good agreement with the measured values, and the method is easy to use; the closer the soil to tunnel is, the faster the lateral horizontal displacement changes; the extent of change of lateral horizontal displacement in longitudinal direction is smaller than displacement in lateral direction.

Abstract: Considering different types of building structure and foundation, the system refers to acceptable ground settlement and acceptable soil loss ratio was established by establishing the control of building’s bending and deformation. The system which adopted Delphi dynamic data binding technology and used Access as database was developed by Delphi7.0 visual tools. The system which named "Analysis system about shield tunnel construction to adjacent buildings" is developed to judge the extent of damage of buildings influenced by adjacent shield tunnel construction.