Effective Stress And Deformation Of Unsaturated Soil - The Strength Characteristics Of The Law

The effective stress of single variation is probably the best approachto simplify the complicated theory of unsaturated soil, and it is alsoprobably the bridge on which the theory of saturated soil can be appliedto unsatllTated soil smoothly. In this paper, researches on the effectivestress of unsaturated soil and its mechhanics characteristics are outspreadfrom many aspects closely around the clue mentioned above.Above all, based on the review about studying actuality of theeffective stress of unsaturated soil and its mechanics characteristics, theformula of effective stress is educed separately from transferring stress ofsoil elements, soil grains and contraction skin according to themechanism of force transferring and mechanics laws. In the formula,parameters of the effective stress in three directions of principle stress aredifferent from each other, which are named as χ₁,χ₂,χ₃separately and each of them is affected by many factors such as thesmicture strength (cemented and embeded force), water volume rate,osmotic suction as well as the surface tension. Thereby the famousBishop's formula of effective stress can be got hold of supplement to alarge extend.The new formula can be expressed by three principle stresses orspherical stress and deviate stress, and the parameter in each of them canbe calculated from the curve of (σ₁-σ₃)─ ε₁, (μ_a-μ_w)─ l and ε₁ and ε_v 西安理工大学博士学位论文一一 el ObtslllCd frofll COllVCfltlOllsl tflgylsl COffipfCSSIOll tCSt Of llllsatllTatCdsoil．Inthls paPaPe瓦 he methods for determlmingthe effective stressparameters andthe conversion relation amongthem as well as thea口＂roach to CXDCXDress strendh．de】口matlon nd stress—stfaln relatlonstil口ofunsaturated soil are put fonvard． Then,by usingthe thought and method melltloned劝ove,the resultsoftrlaxlal andeeetTlaxlal compresslontestsforyangling Intactloess andmaxial collaPslbllltytests for Zhangqlao lfltact loess as well as tests for acommon cbe and eXpanclve soil rom literatures,are calculated andreå’– analysed．The slmpllclty and generallyofthe new effective stressomula cn be Indicated． LastlX the siren寥hparameter c',å·¾'ofunsaturated sollwlthå±±ferent Inltlalwater contelltobtalnedby usingthe conventional rlaxlaltestdataforhglingloess,and·theyare comparedwlththatobtalnedlnså’–ted condition．It shows hat such a conclutlon as" The effectivelè¡€enalfrlctlon angle ofunsaturated soil lsbaslcallyequalto that ofs扯wted soil" Is locallied．Fu讪ermore,he adaPt劝llltyofthe failureconditions ofloess,that the auhor has put forward,Is demonstrated byusingts test data,of向e trlaxlal tests under effective stress conditions。...