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Recently, many studies have been conducted on the stratum deformation induced by earth pressure balance (EPB) shield tunneling in soft soil and sand. Movement laws vary largely among different strata. However, at present, relevant research mainly focuses on soft soil and sand, whereas little attention has been paid to the movement law of round gravel stratum with higher instability. In this study, a field monitoring test was carried out on the EPB shield machine when it passes through the round gravel stratum. Based on the analysis of monitoring results under different chamber earth pressures, thrust force, the torque of the cutter, grouting pressure, and grouting volume, the relationships between shield tunneling parameters and their influence on the disturbance of the surrounding soil mass were investigated. It was found that the surface deformation shape of the monitoring section of the south and north lines conforms to the Gaussian curve. The vertical deformation of the stratum at the tunnel axis is the largest. The maximum value is observed when the cutter head reaches the monitoring section. The horizontal deformation reaches a maximum value at the stage of the shield tail pass section. The strata deformation is not only related to the strata properties but also has a strong positive correlation with the shield tunneling parameters. The chamber earth pressure is the main factor affecting the stratum deformation before the arrival of the cutter head, and the grouting volume is the main factor affecting the strata deformation during the stage of the shield tail pass section.

The bridge of Shanghai Metro Line 10 over Metro Line 6 is a U-shaped concrete single-box double-cell concrete box beam continuous bridge. A novel method is applied to construct the asymmetric cantilever prefabricated and assembled continuous bridge due to the limited construction space and the complex environment. Four mechanical state control methods are applied during the T-shape structure construction process: tensioning pre-stressed steel strand, jacking by the axial force servo system, adjusting the leg reaction force, and setting the auxiliary leg. Auxiliary measures such as the compressive column, side-span counterweight, and temporary pre-stressing are also taken into consideration. The finite element method simulations are performed to measure effects of the four control methods during the construction process. The front leg force of the bridge erection machine and the deflection of the bridge are then monitored. It was deduced that the simulated and measured values of the cantilever T-shape structure are controlled within the limit range during the construction process.

Floating piles have been widely employed as foundations in coastal regions abounding with marine clay. A growing concern for these floating piles is their long-term performance of bearing capacity. To better understand the time-dependent mechanisms behind the bearing capacity, in this paper a series of shear creep tests was conducted to study the effects of load paths/steps and roughness on shear strain of the marine clay-concrete interface. Four main empirical features were observed from the experimental results. First, the creep process of the marine clay-concrete interface can be largely decomposed into the instantaneous creep stage, the attenuation creep stage and the uniform creep stage. Second, the creep stability time and the shear creep displacement generally increase as the shear stress level increases. Third, the shear displacement rises as the number of loading steps drops under the same shear stress. The fourth feature is that under the shear stress condition, the rougher the interface is, the smaller the shear displacement is. Besides, the load-unloading shear creep tests suggest that: (a) shear creep displacement typically contains both viscoelastic and viscoplastic deformation; and (b) the proportion of unrecoverable plastic deformation increases with increasing shear stress. These tests confirm that the Nishihara model can provide a well-defined description of the shear creep behavior of marine clay-concrete interfaces.