Abstract
A non-muck discharge tunnelling method in burial work for small diameter pipe has great advantages such as rapid construction. In considering the application of this method, it is important to clarify the horizontal penetration characteristics in cohesive soil in connection with an apex angle of a penetration model. In this paper, the characteristics in oil based clay and loam deposits are studied by the use of both model testing and a slip line field analysis. The results are summarized as follows:
(1) Oil based clay: The deformation pattern is classified into two tracks; (I) a pattern in which soil slips on a wedge plane of penetration model in the case that the apex angle is smaller than 120°, (II) a pattern in which soil-wedge is produced in the case that the apex angle is greater than 120°. The end resistance and the maximum shear strain of a part away from a penetration model don't depend on the apex angle.
(2) Loam deposits: The smaller the apex angle is, the greater the end resistance becomes.
