Determining the uncertainty associated with the parameters of sensitive clay for geotechnical risk analysis

Saguenay Lac Saint-Jean （SLSJ）地区是由块状和层状两种松散的第四纪粘土地层所覆盖。这些粘土沉积物被归类为敏感粘土，这种敏感粘土的存在会引起诸如运输过程中粘土液化、边坡和地基不稳定等问题。与粘土的物理和力学参数相关的不确定性，在定义与风险相关的岩土和土木工程设计目的的行为方面起着重要作用。因此，本研究的目的是量化SLSJ地区粘土沉积的物理和力学参数的不确定性，并评估138号公路等地区粘土的岩土不确定性对基础设计承载力状态的影响。**因此，将**使用一个数据库，其中包括过去7年来在奇库蒂米quit<s:1> **Chicoutimi大学（UQAC）进行的实验室测试结果，以及MTQ数据库现有的测试结果。将对该区域若干地点的粘土样本进行更多的实验室测试，以**获得更多的数据。将对所有可用数据进行一系列统计分析，以确定每个物理和机械参数的最合适的统计分布，并量化与每个参数相关的不确定性。还将对数据进行回归分析，以**突出物理和机械参数之间可能存在的相关性。这项研究的结果将提供一个概率岩土风险分析，以提高设计和规划的安全水平。**此外，该项目的结果将使公司能够估计SLSJ地区不同位置的粘土特征，从而更好地为项目做准备，更好地预测项目生命周期内可能出现的**问题。

The Saguenay Lac Saint-Jean (SLSJ) region is covered by the stratigraphy of the unconsolidated Quaternary**clay consist of both massive and stratified clay. These clay deposits are classified as sensitive and the presence**of this sensitive clay can cause problems such as, liquefaction of clay in transportation, slopes and foundations**instabilities and etc. The uncertainties associated to the clay's physical and mechanical parameters, play a**significant role in defining its behavior for risk-related geotechnical and civil engineering design purposes.**Therefore, the aim of this study is to quantify the uncertainties associated to each of the physical and**mechanical parameters of the clay deposits at SLSJ region and evaluate the effect of clay's geotechnical**uncertainties on the state of bearing capacity of foundations design in regions like the road 138 project.**Accordingly, a database consists of the results of the laboratory tests conducted at the Université du Québec à**Chicoutimi (UQAC) since the past 7 years, as well as the results of existing tests at the MTQ database would**be used. Additional laboratory tests will be conducted on clay samples from several locations in the region to**obtain additional data. A series of statistical analysis will be carried out on all the available data to determine**the most appropriate statistical distributions for each physical and mechanical parameter, and to quantify the**uncertainties associated to each of the parameters. Regression analysis would also be applied to the data to**highlight possible correlations of physical and mechanical parameters. The results of this study will provide a**probabilistic geotechnical risk analysis to improve the level of safety for design and planning purposes.**Moreover, the results of this project will enable the company to estimate the characteristics of clays at different**locations at the SLSJ region to achieve a better preparation for the projects and better anticipation of the**probable problems during the life time of projects.