各向異性軟土地基極限承載力計算
姜洪偉 張鵬飛 趙錫宏
- 摘 要
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姜洪偉 (中環(huán)投資開發(fā)(集團)有限公司 上海 200063)張鵬飛 趙錫宏 (同濟大學 上海 200092)
[提要] 將土的各向異性不排水剪強度應用到滑移線場理論中,得出不等向固結(jié)(K0固結(jié))粘土地基極限承載力系數(shù)的理論解。對不同試驗條件下的極限承載力系數(shù)及其與K0或 φ‘(有效內(nèi)摩擦角)的關(guān)系進行分析,得到一些有益的結(jié)果。通過模型試驗的計算結(jié)果與實測值的比較,證明本文理論的合理性和有效性。理論分析及計算結(jié)果表明,對于K0固結(jié)粘土,實踐中通常使用的極限承載力系數(shù)Ncu=5.14,如不經(jīng)修正是不適宜的。最后通過現(xiàn)場載荷試驗和工程實例對本文方法和常規(guī)各向同性方法進行了比較分析。
[關(guān)鍵詞] 各向異性 承載力系數(shù) 不排水剪強度 K0固結(jié) 極限平衡
By applying the anisotropic undrained shear strength in the theory of slip lines field, the bearing capacity of strip footings placed on the anisotropically consolidated clays may be evaluated. The bearing capacity factors for various shear tests connecting with K0-value and effective internal friction angle are theoritically analysed and some useful results are obtained. Through comparison between the calculated and measured results from model tests, the validity of present theory is verified. After theoritically analysed, the result shows that for K0-consolidated clay, the isotropic bearing capacity factor( Ncu= 5.14) conventionally used in practice can not be continually used without any correction. Finally, the present method is compared with the conventional method through field test and practical engineering.
Keywords: anisotropy; bearing capacity factor; undrained shear strength; Ko-consolidation