Geotechnical Aspects of Weak Sandstone from Recife/Brazil

In this study an extensive experimental program has been carried out in order to characterize the mechanical behavior of two weak sandstone formations of an offshore field for application to sand production modeling. The experimental tests included Scratch tests, Triaxial tests and Advanced thick wall cylinder tests (ATWC) where the sand production initiation and the cumulative sand produced were registered. Numerical simulations of experimental tests were then performed using an advanced elasto-plastic constitutive model. Triaxial tests simulations allowed calibrating the constitutive model parameters. These parameters were employed for the numerical simulation of the ATWC in order to determine the equivalent plastic strain threshold required to the onset of sand production observed in laboratory for sanding assessment. Results obtained highlight the importance to use a realistic representation of the rock behavior focusing on post-yield behavior in order to build confidence in model predictions.

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Tunnel construction in very weak sandstone

International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts ◽

10.1016/0148-9062(89)92651-x ◽

1989 ◽

Vol 26 (3-4) ◽

pp. A191

Keyword(s):

Tunnel Construction ◽

Weak Sandstone

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Experimental Research on Rheological Property of Water-Bearing Weak Sandstone in Large Cross-Section Tunnelling

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.256-259.1402 ◽

2012 ◽

Vol 256-259 ◽

pp. 1402-1405 ◽

Cited By ~ 1

Author(s):

Ye Zhou ◽

Peng Fei Li

Keyword(s):

Water Content ◽

Cross Section ◽

Rheological Characteristic ◽

Test Results ◽

Large Cross Section ◽

Rheological Equation ◽

Tunnel Face ◽

Water Bursting ◽

The Relationship ◽

Weak Sandstone

Various problems such as sand, mud and water bursting, unstability of tunnel face, large deformation of surrounding rock and severe cracking of primary support occurred in excavation of the water-bearing weak sandstone strata of Huma Ling Tunnel, Lan-Yu railway. Based on the uniaxial compressive strength tests and uniaxial compressive rheological tests on weak sandstone with water content of 0, 2%, 5%, 8% and 12%, the relationship between rheological characteristic and water content of water-bearing weak sandstone is obtained. According to results of tests, factors and water contents are fitted by applying generalized rheological equation of Kelvin. And the rheological equation of water-bearing weak sandstone with various water content is deduced. The test results and conclusion can offer reference for analyzing deformation characteristics and instability mechanism of water-bearing weak sandstone in large cross-section tunnelling.

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