Development of correlation between TCP blow-count and undrained shear strength of high plasticity clay

The Texas Cone Penetration Test (TCP) is mostly used in Texas instead of Standard Penetration Test (SPT) and Cone Penetration Test (CPT), which are widely used in the United States for geotechnical investigation. These tests will give shear strength parameters of soils---cohesion (c u and internal friction angle (&phis;) that are used in the design and evaluation of the stability of many geotechnical structures such as earth slopes, structural foundations and retaining walls. The results of field tests obtained from TCP tests may not be reliable for some field and soil conditions which may result in unsafe design of geotechnical structures. Previously, statistical analysis based models were developed to correlate undrained shear strength and TCP blow counts which do not consider depth and other soil parameters such as moisture content, plastic limit, liquid limit and unit weight of soil.;This research is undertaken to develop a more reliable model which correlates undrained shear strength and TCP blow counts---the derived model is based on the bearing capacity theory and the results of laboratory and field TCP tests Analyzing the data using other soil parameters such as moisture content, plastic limit, liquid limit, unit weight of soil to ascertain how the above factors may influence the TCP blow counts. Advantages, disadvantages and cost of each test (TCP, CPT and SPT) are investigated and discussed in order to determine the most economical and advisable method of testing for that particular geotechnical investigation.;In this research, field and lab data collected by the Texas Department of Transportation (TxDOT), Beaumont District which covered Southeast Texas are used to develop the model. All the collected data are organized in separate data files and filtered according to Unified Soil Classification System (USCS). Updated data are reorganized in separate data files and this data is analyzed using Minitab commercial software. To investigate the soil behavior under the impact of TCP for different types of soils, a numerical model with Mohr-Coloumb plastic analysis is developed using commercially available computer program named FLAC. After simulation of the TCP test, analysis are performed to study the effects of shear strength parameters and to investigate the yielding pattern of each type of soil. Comparison of numerical analysis and statistical analysis are presented in this research. Laboratory tests are performed to validate the correlated results that are derived from the database.