英文篇名
UPDATING UNCERTAINTIES IN SOIL SHEAR STRENGTH PARAMETERS WITH MULTIVARIATE IN-SITU AND LABORATORY TEST DATA
作者
卿建業、陳奕竹、陳皆儒、方國光
關鍵字
不確定性、貝氏分析、經驗公式、摩擦角、不排水剪力強度、機率密度函數
摘要
近年來,大地工程師對於可靠度設計愈來愈重視,而土壤不確定參數的機率密度函數(probability density function, PDF)是可靠度設計所不可或缺的,如何根據已知資訊得到土壤強度參數PDF是一個重要的研究課題,雖然我們可以根據精密的實驗室實驗得到土壤強度參數,譬如根據砂土排水三軸實驗得到摩擦角,然而此類實驗室實驗大多相當昂貴且耗時,反觀一些其他現地及實驗室實驗相較之下則較為便宜且快速。不過這些實驗通常不會直接地提供土壤強度參數的資訊,但仍可藉由土壤參數間的關係間接地提供土壤強度參數的資訊。本研究試著回答下列問題:給定不只一種現地或實驗室實驗資料,要如何結合這些資料所提供的資訊進而更新土壤強度參數的PDF?本研究成果對於大地工程的可靠度設計將有所助益。
英文摘要
In recent years, geotechnical engineers have paid much attention on reliability-based design. The probability density functions (PDFs) of the uncertain soil parameters are required for the reliability-based design. Among the soil parameters, soil strengths play important roles in geotechnical design, e.g. friction angle of sand and undrained shear strength of clay. How to obtain those PDFs based on all available information is an important research subject. It is possible to establish the PDFs of the soil strengths based on results from sophisticated laboratory tests, e.g. drained test for sand to obtain its friction angle, but those tests may be expensive and time consuming. On the other hand, some in-situ and laboratory tests are quick and convenient, but they usually do not provide direct information on the soil strengths. Nevertheless, they do usually provide indirect information of the soil strengths by correlation. This research tries to answer the following questions: Given the in-situ and laboratory test data of more than one kind, how do we combine the information contained in those data and update the PDFs of the soil strengths? The results of this research will be beneficial to geotechnical reliability-based design.