Ground settlement is often the most serious concern when tunneling under an old city with numerous historic monuments. A successful engineering design under these conditions would require getting the most out of the ground strength parameters and avoiding any weakening maneuver throughout the operation. Knowing that surface settlement is highly affected by tunneling parameters in EPB shield tun...

Propagation of an electromagnetic ground wave over a plane surface in which the argument of the surface impedance is greater than n/4 but ; A less than TT/2 is considered in some detail. The numerical distance, p, over such a surface is characterized by 0 f arg p £ n/2 . The ground wave behaves in a rather unusual manner, and this is attributed to the interaction of phasors representing a trapp...

Tunnelling through cities underlain by soft soil, commonly associated with soil movement around the tunnels and subsequent surface settlement. The predication of ground movement during the tunnelling and optimum support pressure could be based on analytical, empirical or the numerical methods. The commonly used Earth pressure balance (EPB) tunneling machines, uses the excavated soil in a pressu...

Downward looking ground penetrating radar (GPR) has been considered a viable technology for landmine detection. For such a GPR with the antennas positioned very close to the ground surface, the reflections from the ground surface, i.e., the ground bounce, are very strong and can completely dominate the weak returns from shallowly buried plastic mines. Hence, one of the key challenges of using G...

Using density functional calculations, we found that the ground state configuration of some bcc(001) surfaces are field dependent because different configurations experience different Stark shifts of surface states. When the W(001) surface is positively biased, an external electric field stabilizes a cs2 3 2d array of surface vacancies, so that the ground state is no longer the well-established...

The potential positive effects of ground proximity on the aerodynamic performance of a \Ving or aerofoil have long been established, but at transonic speeds the fonnation of shock waves betvveen the body and the ground plane would have significant consequences. A numerical study of the aerodynamics of an lu\E2822 aerofoil section in ground eiiect flight was conducted at freestream Mach numbers ...

The addition of multimodal feedback during navigation in a virtual environment is fundamental when aiming at fully immersive and realistic simulations. Several visual, acoustic, haptic or vibrotactile perceptual cues can be generated when walking over a ground surface. Such sensory feedback can provide crucial and varied information regarding either the ground material itself, the properties of...

A solution technique for the dynamic analysis of asymmetric base-isolated buildings, subject to earthquake ground motion, is presented. To develop the formulation, a yield surface as a function of both shear force and torsion moment of the sliding surface with rigid perfectly plastic behavior is constituted. To achieve the objective, the yield stress is defined by the friction coefficient throu...

this paper gives an account of the implementation of geomorphological, hydrogeological, hydrochemical and isotopic techniques to understand groundwater-surface water interactions in a multiple use area, los padres-la brava corridor (se of buenos aires province, argentina). the isophreatic map reveals a regional flow from the sw to ne sector, and allowed us to define the effluent-influent behav...