The Application of the Strength Reduction Method in Site Stability Analysis of CCS

• Wei Yuan，Xiaochun Li，Bing Bai

Abstract

The factor of safety (FOS) as a technical index, especially adopted in slope engineering, is widely used in the stability evaluation of geotechnical engineering. It is popularly accepted because of its conciseness and straight forward physical meaning. However, very little analysis of this concept has been found for a large scale site involving regional structural geology. In this paper, FOS was introduced into the stability analysis of the site during CO2 injection. To get this FOS, the strength reduction technique was used. In most existing engineering projects, shear failure is the most usual mode in rock mass, but the tensile failure may also occur in certain areas which means that tensile failure should also be taken into consideration in strength reduction methods. Hence a tensile-shear strength reduction method which claims that the tensile strength, friction angle and cohesion should satisfy an inequality during the strength reduction process is put forward. This new strength reduction method was applied to the geological sequestration of CO2 to acquire the FOS of the stratum during the CO2 injection process. What makes this new method unique is that it can be presented with an evolution history of FOS during the whole injection process.

https://link.springer.com/chapter/10.1007%2F978-3-642-37849-2_22#citeas

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