Due to rapid industrial development, underground excavation work is rapidly increasing, and the application of earth retaining methods to minimize the surrounding impact caused by underground excavation is becoming common. In the earth retaining metho...
Due to rapid industrial development, underground excavation work is rapidly increasing, and the application of earth retaining methods to minimize the surrounding impact caused by underground excavation is becoming common. In the earth retaining method, the safety of the excavation bottom must be ensured simultaneously with penetration depth and safety against boiling phenomenon for all soil layers except the soft cohesive soil layer.
Among the review methods presented in the temporary earth retaining design standards and underground safety evaluation standard manual, the safety factor of penetration depth takes cohesion into consideration. Since the boiling review formula has limitations in that it does not take adhesion into consideration, research on boiling review formulas that take adhesion into consideration is required.
The direction of the study is that if the review standard requires that the stability condition for the penetration depth and the stability condition for the boiling phenomenon be satisfied simultaneously in cohesive ground conditions, the wall penetration depth is excessive due to the limitations of the boiling review equation that does not take cohesion into account. Since there is a problem with the calculation, existing theories were reviewed to supplement this.
A rational research direction that can satisfy both conditions at the same time by analyzing various earth pressure equations and analysis methods for determining penetration depth presented in the design standards for temporary retaining facilities and the standard manual for underground safety evaluation, and analyzing various theoretical equations and standards for boiling review.
In order to propose a reasonable review formula that can be applied to cohesive ground conditions, an indoor model experiment was conducted and the results were analyzed to determine the flow characteristics of water in the soil and calculate the safety factor. The conventional theoretical formula and the researcher's proposed formula were used. The safety factor was calculated using.
Through analysis of the research results, a boiling review equation considering cohesion was studied to enable a reasonable design when simultaneously reviewing measures to secure safety for penetration depth and boiling phenomenon in cohesive ground.
Proposal of a modified version of Terzaghi's simple formula that can take adhesion into account, and verification of adequacy through measurement management results and reverse analysis through application cases of the proposed review formula.