Determination of Active Zone in Expansive Clay in North Texas through Field Instrumentation

Infiltration of rain water into soil is expected to decrease matric suction in unsaturated soil which may reduce the shear strength of soil at the moisture variation zone and may reduce the factor of safety of earth slope. Therefore, it is important to identify the depth of moisture variation zone to accurately predict the stability of earth slopes constructed on expansive clay. The objective of the current study is to determine the depth of moisture variation zone of earth slopes constructed on highly expansive clay in Midlothian, Texas. The study also investigates field infiltration behavior of different rainfall events with varying intensity and duration. The site was monitored over a period of 4 years with a rain gauge, six moisture sensors and six water potential probes for rainfall, moisture content and suction respectively. The field monitoring data indicated that the moisture variation zone extends up to a depth of 3.6 m, with the highest infiltration at the crest of the slope. The instrumentation data also revealed that low intensity, long duration rainfall results in delayed penetration of rainwater. Infiltration of rainwater was also found to be dependent on the initial distribution of matric suction

• Supplemental Notes:
  • This paper was sponsored by TRB committee AFP60 Standing Committee on Engineering Behavior of Unsaturated Soils.
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Hossain, Jubair
  • Khan, Mohammad Sadik
  • Hossain, MD Sahadat
  • Ahmed, Asif
• Conference:
  • Transportation Research Board 95th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2016-1-10 to 2016-1-14
• Date: 2016

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; Photos; References; Tables;
• Pagination: 25p
• Monograph Title: TRB 95th Annual Meeting Compendium of Papers

Subject/Index Terms

• TRT Terms: Depth; Embankments; Expansive clays; Field studies; Infiltration; Instrumentation; Rainfall; Slope stability; Soil suction; Soil water
• Uncontrolled Terms: Matric suction
• Geographic Terms: Midlothian (Texas)
• Subject Areas: Geotechnology; Highways;

Filing Info

• Accession Number: 01593893
• Record Type: Publication
• Report/Paper Numbers: 16-2505
• Files: TRIS, TRB, ATRI
• Created Date: Mar 18 2016 12:38PM