Advanced Materials Research Vols. 671-674

Abstract: Based on a dual-wall steel cofferdam, the configuration character and construction technology of the dual-wall steel cofferdam was introduced. The load of different construction stages of the steel cofferdam was studied. The mechanical properties of this structure under every construction stage were analyzed by the finite element method. Analytical result reveals that the maximal Von Mises stress of the dual-wall steel cofferdam was 197.73 MPa under the action of the most disadvantaged load combination. That met the strength requirements of the temporary structure.

Abstract: In order to analyze the influence of different compaction methods on bridge deck vibration and bridge pavement compaction quality, the field test and laboratory test of oscillating compaction and vibrating compaction were carried out. The results demonstrated bridge deck vibration caused by the intrinsic exciting force of compactor contributed to vibrating compaction. On the pattern of oscillating compaction, the disturbance of bridge deck due to the exciting force of compactor is the main factor to induce bridge vibration. Furthermore, the vibration acceleration and amplitude in lateral, longitudinal and vertical direction, oscillating compaction are much smaller than that of vibrating compaction. Compared with vibrating compaction, the rolling efficiency of oscillating compaction is obviously higher and the final compaction degree also is much higher. Besides that, phenomenon of crushing the coarse aggregate is exists in the compaction construction, in which the effect of vibrating compaction on crushing the coarse aggregate is more obvious than oscillating compaction, and the range of crushing the coarse aggregate caused by vibratory compaction is larger than oscillating compaction.

Abstract: In order to study the Dalian Metro section 202(Cujin Road station-Chunguang Street station, which is shallowly buried and covered with plain fill)’s ground surface settlement, the monitoring measuring station was built during the construction. After 3 months’ measuring by precision level,the data shows that the maximum point is in the center line of the tunnel of the upper part. The settlement is about 25.66-31.82mm. This paper put forward the concept of the distance span ratio β, β effective value range was - 4 <β< 4,Surface subsidence is closely related with β, Severe surface subsidence stage is -2 <β< 2, Occupy whole deformation is 67.5-77.6%,settlement rate about 0.84-0.93mm/d, so should strengthen the monitoring frequency, Suggest increases site tour. Field test results and the ground surface settlement calculation model winkle are identical with each other; the monitoring results have important guiding significance and reference for Dalian subway and the similar shallow depth excavation tunnel construction.

Abstract: In the present paper, we consider the floating problem of river-crossing shield tunnel in the process of construction. Firstly, based on the theoretical analysis of equilibrium states of excavation face and shield segments away from shield tail, we obtain the equation for calculating the minimum thickness of overlying soil in the associated equilibrium states. Secondly, the above derived formula are applied in the Fuhe bridge project, which is a sub-project of No.1 Nanchang metro; at the same time, numerical simulation is carried out to further evaluate the safety with the change of overlying soil thickness. Lastly, some useful conclusions are drawn through comparative study, which is helpful to similar projects.

Abstract: In urban environment, short-distance crossing of shield tunneling to existent piles is an unloading process and can cause adverse effect on the piles. This kind of effect should be controlled. To analysis and control this effect, numerical simulation, field monitoring and optimization of construction parameter were used in this study. To get reasonable calculation parameters for numerical models, field monitoring was conducted. The numerical simulation was utilized to study the process of short-distance crossing and the effect of ground improvement with rotary jet grout pile. The simulation result revealed that the ground improvement is not necessary in soft soil if the pile is long enough. In the later practical tunneling process, the ground improvement in the initial design was canceled. Construction parameters were adjusted in time, such as the strict controlling of synchronized grouting, secondary grouting, rotation speed of cutter head and driving speed. As a result, the displacement of the existent piles was controlled in the tolerable ranges.

Abstract: The analytic solution for circular tunnel under asymmetry load usually uses C-M criterion, and the finite element calculation usually uses D-P criterion. In this paper, the complex variable function method is employed to do an elastoplastic analysis based on Tresca Criterion, obtained the stress and plastic radius in elastoplastic region. The result shows that extent of stress in elastic region is no longer match the Krisch solution. The solution is in good agreement with Sun GZ’s solution and finite element simulation based on ANSYS, which can be used in simple elastoplastic analysis of surrounding rock instead of finite element method.

Abstract: Take the one-third of the allowable values as the basic value. The control standards of the ground subsidence is 30mm, and the control standards of the ground swell is 10mm. Take one typically stretch of sites as research object by the buried depth and plane disposition condition. Take ten sections and the kilometer post. Consider 52 contents as of an analysis. The maximum subsidence is mostly kept within 13mm. The monitoring data of each lateral section are certain differences because of the different gemological conditions, the water quality, soils covered and so on. When the shield drives off the monitoring section, the subsidence is about 6mm~16mm and 50% of the total subsidence. The main subsidence appears after the shield tail pass out for sand.

Abstract: The Guangzhou Subway System adopts a planning scheme that guides passengers through a system of symbolic colors for its routes. However, the designers seem to have neglected color blind's difficulty in distinguishing some hues when selecting the routes' symbolic colors, which suggests that color universal design theories are not properly applied in their design work. This research aims at evaluating Guangzhou Subway’s symbolic color and guidance system from the color universal design perspective. We use the Vischeck[1] to simulate and analyze the practical situation. In accordance with the analysis, solutions are recommended.

Abstract: This essay analyses the design of Stockholm Metro in Sweden, focusing on its planning and design of public art. Under special cultural background, Stockholm Metro has its own comprehension of public art and design. The design has successfully solved problems by giving vivid guidance to passengers in several ways: the use of colour decoration in stations, personalized designs of spaces and the changes of passengers’ sensory focuses, which are valuable to improve the management and the transportation quality of Metro in China.

Abstract: Water-bearing fault of subsea tunnel has fissure water developed, fractured surrounding rock with low strength, which gets a risk of sudden water inflow and affects the tunnel security. This paper takes the geological forecast and treatment for water-bearing fault of the Qingdao kiaochow bay subsea tunnel for example, according to the water assignment characteristics, using the detect method of TEM and advance borehole to make accurate decision for the position of water-bearing body、the scale of fracture zone and the inflow of water. Through the analysis of results, the grouting form, materials and parameters are chosen and adjusted. The grouting material seals the water flowing fracture, forming water-stopping curtain outside tunnel excavation contour line and strengthening the fault fracture zone to improve the stability of rock.