中文摘要：

主教有效应力或二个州的压力变量为液体阶段之一是不连续的不饱和的土壤是不能令人满意的，因此有效应力的新表情应该被成立。为推导的途径根据力量的平衡的原则(即，分享压力的原则) ，并且它被表明有效应力的 TERZAGHI 原则第一验证。然后，推导根据不同毛孔空气状态被细分进四部分：1 ) 空气水泡在毛孔水里球形、推迟；2 ) 空气水泡对土壤约束力骨骼；3 ) 空气水泡几乎保持了毛孔的单个节；4 ) 空气阶段是连续的。有效应力的不同公式被介绍。结论如下被得出：1 ) 为将近浸透的土壤，真实有效压力将比 TERZAGHI 有效应力小一些；2 ) 在水泡形式为在哪个让阶段通风的土壤是不连续的，毛孔空气橡皮压力的一个新概念被提出，并且全部的压力能被有效应力，毛孔水压力和毛孔组成空气橡皮压力；3 ) 为空气阶段是连续的在土壤，有效应力等于全部的压力的价值正吸；4 ) 吸能被划分成二部分：一个人是另外的压力引起的效果，并且其它是用皮肤的合同行动。

英文摘要：

BISHOP＇s effective stress or two state stress variables are unsatisfactory for unsaturated soils where one of fluid phases is discontinuous, so new expressions of effective stress should be founded. The approach for derivation was according to the principle of equilibrium of forces （i.e., the stress-sharing principle）, and it was firstly validated by demonstrating TERZAGHI＇s principle of effective stress. And then, the derivations were subdivided into four parts according to different pore air states： 1） air bubbles were spherical and suspended in pore water; 2） air bubbles were bound on soil skeleton; 3） air bubbles held almost the single section of pore; 4） air phase was continuous. The different formulae of effective stress were presented. Conclusions are drawn as follows： 1） For nearly-saturated soils, the ＂real＂ effective stress would be a little smaller than TERZAGHI＇s effective stress; 2） For soils in which air phase is discontinuous in the form of bubbles, a new concept of pore air elastic pressure is put forward, and the total stress can be constituted by effective stress, pore water pressure and pore air elastic pressure; 3） For soils in which air phase is continuous, effective stress is equal to the value of the total stress plus suction; 4） Suction can be divided into two parts： one is the effect caused by additional pressure, and the other is the contract action by the ＂skin＂.