Stabilising the cohesive soil with palm fibre sheath strip

Abstract

A multiple regression model was used based on experimental data using regression analysis method to predict the strength of Shanghai cohesive soil reinforced with strips of natural palm sheath strips. Four different variables were studied to investigate the behaviour and strength of reinforced cohesive soil with palm sheath strips. These are the content, size and aspect ratio of palm sheath strips as well as the normal stress applied in the shear tests. For this purpose, a series of direct shear tests were conducted on unreinforced and reinforced soil specimens. Test results showed that using strips of natural palm sheath improved the strength of the tested soil. Increasing content of palm sheath has a more significant effect on the enhancement of residual strength compared to the enhancement of peak shear strength. Content, size, aspect ratio of palm sheath strips and the normal stress applied have significant effects on the improvement of both peak and residual strength. Utilisation of such natural palm sheath in this way will help in preparation of green composites as well as reducing the cost of ground improvement. Results showed that multiple linear regression models can accurately predict the strength of Shanghai cohesive soil reinforced with local palm sheath strips within the range of the studied variables and type of soil tested in this paper. Consequently, using such regression models will save time as well as reduce laboratory costs.

Keywords:

• reinforced soil
• palm sheath
• peak strength
• residual strength
• regression model

Acknowledgement

We would like to acknowledge the following people from University of Shanghai for Science and Technology: Chencai Li for the valuable contribution on data elaboration and analyses. Thank you also to beibei Li for technical support in testing procedure.

Disclosure statement

No potential conflict of interest was reported by the authors.

Funding

The Project was funded by Shanghai Kcone Consulting and Management Co. Ltd. grant no. 3A-11-307-110. Data used in the analyses on Properties of palm fibre sheath (Table 1) is provided by YiYing Testing Co. Shanghai, China.