層狀黏土中淺基礎極限承載力探討

Study of Ultimate Bearing Capacity of Shallow Foundation on Layered Soils

林志盈(Jing-Ying Lin)

指導教授 ： 馬正明

義守大學/理工學院/土木與生態工程學系/碩士(2016年)

摘要

極限承載力與沉陷量分析為結構物基礎設計中兩種最基本之設計項目，極限承載力在一般均質土層中已有明確之理論分析，但是一般地層皆為層狀土壤，在層狀土壤中之極限承載力分析尚未有所定論，仍然有探討研究之比要。此次研究主要探討對象為層狀土壤的極限承載力分析，以有限元素分析程式探討各種層狀土壤中之極限承載力。
首先分別探討單一堅硬與軟弱黏土個別之極限承載力，接著在堅硬黏土與軟弱黏土互層狀況下，以有限元素分析程式探討基礎重與沉陷量之關係，並進一步求得層狀黏土之極限承載力，在此研究中，需探討堅硬與軟弱黏土各具有不同之厚度、不同之排水剪力強度與彈性模數等設計參數，經過整理分析後可以得到層狀黏土之極限承載力與個別黏土極限承載力之關係(互層承載力參數) ，如此即可對層狀黏土之極限承載力有完整之了解。

關鍵字

極限承載力 ； 層狀土壤 ； 不排水剪力強度 ； 彈性模數 ； 堅硬與軟弱黏土

並列摘要

Ultimate bearing capacity and settlement analysis are two of the most important design items in the foundation design of structure. In homogenious sils, the theory for ultimate bearing capacity is very clear. But in the layered soils, the ultimate bearing capacity theory has not been to a definite conclusion. More research effort could be entered in this subject. In this research, the main objective is the ultimate bearing capacity of the layered soils. Finite element method will be adopted to obtain the ultimate bearing capacity for layered soils in several different cases.
The ultimate bearing capacity for single stiff clays and soft clays was respectively studied first. In the case of interlayer soils of stiff clays and soft clays, finite element method was adopted to obtain the relationship of foundation load and settlement and then the ultimate bearing capacity for layered clays. In this research, stiff clays and soft clays were with different stratum thickness, undrained shear strength and elastic modulus etc.. Therefore the ultimate bearing capacity for layered clays could be obtained in terms of ultimate bearing capacity of stiff clays and soft clays respectively. Therefore the complete understanding for ultimate bearing capacity of layered soils could be reached.

並列關鍵字

ultimate bearing capacity ； layered soils ； undrained shear strength ； elastic modulus ； stiff and soft clays

參考文獻

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