The process of shield tunnel excavation would inevitably cause surrounding ground movement, and excessive displacement in the soil could lead to large deformation even collapse tunnel. methods estimating convergence around opening is summarized. Then, a universal pattern boundary condition cavity originally introduced, which solved as combination three fundamental modes, namely, uniform converg...

In this paper, a control approach called Artificial Neural Tissue (ANT) is applied to multirobot excavation for lunar base preparation tasks including clearing landing pads and burying of habitat modules. We show for the first time, a team of autonomous robots excavating a terrain to match a given 3D blueprint. Constructing mounds around landing pads will provide physical shielding from debris ...

This paper takes the effect of supporting structure and anchor on the slope stability of the excavation process into consideration; the stability calculation model is presented for the slope reinforced by prestressed anchor and grillage beam, and the dynamic search model of the critical slip surface also is put forward. The calculation model of the optimal stability solution of each anchor tens...

PURPOSE To study the prevalence and 3-dimensional (3-D) tomographic features of focal choroidal excavations in eyes with central serous chorioretinopathy (CSC) using swept-source optical coherence tomography (OCT). DESIGN Prospective, cross-sectional study. METHODS We examined 116 consecutive eyes with CSC with a prototype 3-D swept-source OCT. 3-D images of the shape of the macular area, c...

This paper deals with full face excavation of large size tunnels in rock masses of very poor quality which exhibit squeezing problems. Three different time dependent constitutive models of increasing complexity (a viscoelasticplastic model, an elastic-viscoplastic model, and an elastic-plastic-viscoplastic model) are used to analyze the tunnel response during excavation of the Saint Martin La P...

Background and objectives : To evaluate the efficacy of chemo-mechanical method (carisolv) of caries removal with that of hand cutting and rotary cutting instruments with the help of knoop hardness measurements of the cavity floor. Method : The 45 carious molars were subjected to caries detector (Kavo DIAGNOdent) to assess the extent of the lesion before and after the study. The selected sample...

With the development of urban metro systems, shield tunnels that pass through existing bridge pile foundations have become an inevitable engineering problem. Therefore, ensuring stability strata and piles during tunnel construction is a common goal in practice. Currently, research on mechanical responses under different conditions upper-soft lower-hard composite tunneling has not been conducted...

This article investigates and presents a case study on the Beijing Subway Line 12 excavation beneath existing Qinghuayuan Tunnel. The composite pre-reinforcement technique was used in conjunction with shallow tunneling method to control distortion of large-diameter tunnel. When building twin tunnels underneath, this strategy considerably decreased impact To systematically mechanical response tu...

During the excavation of a gallery in 2003 in the Tournemire argillite, a mine-by-test experiment has been performed, enabling measurements of pore pressure and displacements during the excavation (short term) as well as nearly three years after (long term). From these data, it has been possible, by means of bidimensionnal simulations, first to calibrate hydro-mechanical parameters, and then, u...