Application Study Of Drucker-prager Yield Criteria To Geotechnical Stability Analysis

The yield and failure of geomaterials are not only the most fundamental but also the mostimportant problems in geotechnical engineering.The applications of yield criteria have alwaysbeen the hottest research topic, then vast research has been carried out and abundantachievements have been acquired. The Drucker-Prager yield criteria are widely used ingeotechnical engineering as modified models of Mohr-Coulomb criterion.Great differencesmay be made between results with different Drucker-Prager yield criteria. In order to establishthe essence of strength reduction theory, this paper compares various Drucker-Prager yieldcriteria and selects a formula that best serves its needs.It proposes the surrounding rockexcavation damaged zone distribution laws of deep tunnel on the base of Drucker-Prager yieldcriteria and a new slope safety factor conversion formula with different Drucker-Prager yieldcriteria was deduced. The main study and results are listed as follows:(1)After comparing the differences of materials between metals and geomaterials andreviewing the corresponding yield criteria, the Mohr-Coulomb criterion and its modifiedmodels are discussed.The relationships between different Drucker-Prager criteria and theirphysical implication are studied systematically.The transformation method of differentDrucker-Prager yield criteria was put forward and its essence is strength reduction theory.(2)Support theory for excavation damaged zone are introduced in details.Based on theanalysis of yield and failure of materials, it’s concluded that this two conceptions aredifferent.The excavation damaged zone distribution laws of tunnel are proposed on basis ofDrucker-Prager yield criteria.Taking the construction of Shengrenshan tunnel as an example,the paper adopts sit monitoring together with3D numerical simulations to analyze thestability rules of rock-mass in different zones.Studies of section how to select a properDrucker-Prager yield criteria are made.(3)The strength reduction finite element method(FEM) is introduced and the definition ofslope stability safety factor based on Drucker-Prager yield criteria was adopted. A new slopesafety factor conversion formula with Different Drucker-Prager yield criteria was deduced and its correctness was examined by comparing results of different criteria in somereferences.