Research on Presumption of the Execution Loads on Segments

Mitsutaka SUGIMOTO

It had been confirmed through the previous researches that the kinematic shield model could express actual shield behaviors .
According to the construction results, the ground water leakage into the tunnel occured at the sharp curved tunnel alignment due to the tunneling execution loads on segments, which comes from the decrease of tail clearance. To make clear its influence on segments, it is necessary to develop the model, which can represent the force acting on tail accurately.
Therefore, this research aims to improve the kinematic shield model so as to estimate the execution loads on segments quantitatively. The validity of this model was verified by the execution data.
As a result, the followings were concluded.
1)The model that represents a deformation of steel segment and the position of segment more clearly was developed.
2)The simulation on shield behavior was carried out by using the measured data during the slurry type articulated shield excavation at the sharp curved alignment. As a result, the simulated shield machine behavior has a good agreement with the observed one. This demonstrates the validity of the newly improved shield kinematics model.
3)This model can represent the change of jack thrust when wire brush passes at main girder of segment and at segment skin plate deformed by execution loads.
Then, this shield kinematic model enables us to evaluate the execution loads on segments more accurately.