The results show that the rock reaction and consequently the shear load on rock bolt in the analytical model is underestimated (by up to 50% in case of high strength concrete).
These numerical models are compared with the analytical model proposed by Pellet and Egger ( 1996). The calibrated numerical models were used to study the state of stress along the rock bolt under different concrete strength. Results from double shear laboratory tests by Kostecki (2019) have been used to calibrate the numerical models in ANSYS (ANSYS® Academic Research Mechanical 2019). These models need to be modified to simulate the actual rock bolt response as determined under laboratory testing. However, currently available structural support models do not accurately model the rock bolt behaviour under shear loads. Calibrated numerical modelling can be an important tool for simulating the rock bolt response under in situ loads. The calculated result shows that the displacement of WenXiang tunnel locating on the line of ZhengZhou-Xi’an Railway High-speed can be well controlled by adopting the excavation method of layering excavation at vertical direction and section excavation at longitudinal direction, which makes the safety of serviceability state of extension of expressway and the operation of Railway High-speed.Determining the rock bolt response under the typical in situ loading conditions of tension, shear and bending is an important part of the support design process.
In the profile plot, usually displacement of the invert arch is less than that of the vault, and affected by the mutual position of topography and excavation, the maximum displacement, 6.3mm, merges at 50m of the vault in the profile plot in the cross-section plot, due to occurrence of unloading effect brought by overlying excavation, tunnel structure has the tendency of rising toward the excavation. In this paper, from two aspects, the deformation of profile and cross-section, serviceability state is analyzed in detail. The above results provide a reliable basis for the future research on the dynamic response of caisson foundation.Ībstract: Based on the typical adjacent project of extension of LianHuo expressway which is constructed on WenXiang tunnel, the finite difference software, Flac3D, is adopted to stimulate the process of the construction. Looked from the overall,the anti-seismic property of the caisson foundation is good. We sure the bond of the caisson foundation bottom and the below soil layer is firm and the relative displacement is only 1.3 mm.
Through the analysis on these curves, we know the maximum values of the acceleration, the velocity and the displacement of the top portion of the caisson foundation are 393.6 cm/s 2, 75.9 cm/s, 28.5 cm, and the maximum rotation angle of the caisson foundation is 0.08°.
We also obtain the rotation angle time-history curve and the relative displacement time-history curve of two key points at the bottom of the caisson foundation. By applying the horizontal (x direction) seismic waves at the bottom of the model, we simulate the earthquake action to the caisson foundation and the soil body around it and obtain the time-history curves of the acceleration, the velocity and the displacement of the key points in the model in x direction.
#Plot flac3d software
Abstract: Based on the software FLAC3D, we set up the dynamic calculation model.
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