Search

In this paper, under the generalized assumptions of the memory kernel function, using the idea introduced by Lasiecka and Wang (Intrinsic decay rate estimates for semilinear abstract second order equations with memory. Springer INdAM Series 10, New Prospects in Direct, Inverse and Control Problems for Evolution Equations, Chap. 14, Springer, Switzerland, 2014) we prove the general decay result to an initial boundary value problem of a wave equation with variable density. Our general assumptions of the memory kernel function generalize the assumptions in the literature (Alabau-Boussouira et al. in J Funct Anal 254(5):1342–1372, 2008; Messaoudi and Khulaifi in Appl Math Lett 66:16–22, 2017). [ABSTRACT FROM AUTHOR]

When planning a TBM drive in squeezing ground, the tunnelling engineer faces a complex problem involving a number of conflicting factors. In this respect, numerical analyses represent a helpful decision aid as they provide a quantitative assessment of the effects of key parameters. The present paper investigates the interaction between the shield, ground and tunnel support by means of computational analysis. Emphasis is placed on the boundary condition, which is applied to model the interface between the ground and the shield or tunnel support. The paper also discusses two cases, which illustrate different methodical approaches applied to the assessment of a TBM drive in squeezing ground. The first case history-the Uluabat Tunnel (Turkey)-mainly involves the investigation of TBM design measures aimed at reducing the risk of shield jamming. The second case history-the Faido Section of the Gotthard Base Tunnel (Switzerland)-deals with different types of tunnel support installed behind a gripper TBM. [ABSTRACT FROM AUTHOR]

The paper derives analytical solutions for deformation of viscoelastic pipe in elastic soil under far-field principal stress increments. These solutions are validated in laboratory tests and numerical analysis and provide the basis for back-calculation of earth pressure increments from measured changes in shape of an inclinometer pipe cross-section using inclinodeformeter (IDM) technology. The procedure has been applied to back-calculating earth pressure changes and soil stiffness in three creeping landslides in Switzerland, which are similar in size but have a range of different boundary conditions and displacement rate fields. In these applications, pressure increments of less than 1 kPa could be reliably back-calculated allowing for identification of compression and extension zones, as well as yielding and failure of soil in the landslides under study, confirming the previously developed models of the landslide mechanisms and suggesting that IDM pressure measurements could serve as a reliable tool for analysis and monitoring of creeping landslides. [ABSTRACT FROM AUTHOR]