土木工程岩土工程裂隙岩体毕业论文中英文资料对照外文翻译文献综述
surcharge is applied to the structure, the speci c weight γ of the constituent material will obviously constitute the sole loading parameter of the system.Assessing the stability of this structure will amount to evaluating the maximum possible height h+ beyond which failure will occur. A standard dimensional analysis of this problem shows that this critical height may be
put in the form
where θ=joint orientation and K+=nondimensional factor governing the stability of the excavation. Upper-bound estimates of this factor will now be determined by means of the
yield design kinematic approach, using two kinds of failure mechanisms shown in Fig. 4.
Rotational Failure Mechanism [Fig. 4(a)]
The rst class of failure mechanisms considered in the analysis is a direct transposition of those usually employed for homogeneous and isotropic soil or rock slopes. In such a mechanism a volume of homogenized jointed rock mass is rotating about a point Ω with an angular velocity ω. The curve separating this volume from the rest of the structure which is kept motionless is a velocity jump line. Since it is an arc of the log spiral of angle mand focus Ω the velocity discontinuity at any point of this line is inclined at angle wm with respect to the tangent at the same point.
The work done by the external forces and the maximum resisting work developed in
such a mechanism may be written as (see Chen and Liu 1990; Maghous et al. 1998)
where weand wme=dimensionless functions, and μ1 and μ2=angles specifying the