Field monitoring of mechanically stabilized earth walls to investigate secondary reinforcement effects.

Details

• Creators:
  Jiang, Yan ; Han, Jie ; Parsons, Robert L. ; Cai, Hongyi
• Corporate Creators:
  University of Kansas. Dept. of Civil, Environmental and Architectural Engineering
• Subject/TRT Terms:
  • Earth walls
  • Soil stabilization
  • Earth pressure
  • Reinforcement (Engineering)
  • Geogrids
  • Deflection
  • Tension
  • Field tests
• Publication/ Report Number:
  KS-15-09
• Resource Type:
  Tech Report
• Geographical Coverage:
  Kansas
• Corporate Publisher:
  Kansas. Dept. of Transportation. Bureau of Research
• Abstract:
  Mechanically stabilized earth (MSE) walls have been commonly used in highway construction. AASHTO (2007) has ; detailed design procedures for such a wall system. In the current AASHTO design, only primary reinforcements are used in ; relatively large spacing (commonly 2 feet), which requires higher connection strength between reinforcements and wall facing. ; Large spacing between reinforcements may also increase the chances of wall facing bulging and construction-related problems. To ; alleviate such problems, the use of secondary reinforcements installed between primary reinforcements was proposed. The use of ; secondary reinforcements could (1) reduce the required connection load for primary reinforcement, (2) increase the internal ; stability by secondary reinforcement, (3) improve the compaction near the wall facing, and (4) mitigate the down-drag behind the ; wall facing. However, this idea was not verified in practice. ; To improve the understanding of the performance of MSE walls with secondary reinforcement and verify its benefits in ; practice, three MSE wall sections reinforced with geogrids were constructed and monitored in the field: (1) an MSE wall section ; with uniaxial geogrids as primary and secondary reinforcements, (2) an MSE wall section with uniaxial geogrids as primary ; reinforcements and with biaxial geogrids as secondary reinforcements, and (3) an MSE wall section with uniaxial geogrids as ; primary reinforcements only (i.e., the control section). Earth pressure cells, inclinometer pipes and a probe, and foil-type strain ; gauges were used in these three test wall sections to measure the vertical and lateral earth pressures, lateral wall facing deflections, ; and strains of primary and secondary geogrids, respectively. The measured results (i.e., the wall facing deflections, the vertical and ; horizontal earth pressures, and the strains of geogrids) were compared with those calculated using AASHTO (2007). ; Based on the analysis of the field test results, major conclusions can be drawn in the following: (1) the secondary ; reinforcements reduced the wall facing deflections as compared with those in the control section; (2) the measured vertical earth ; pressures were close to the computed trapezoid stresses and increased with the construction of the wall; (3) the distribution of the ; measured lateral earth pressures in the control section linearly increased with depth, while the distributions of the measured lateral ; earth pressures in the sections with secondary reinforcements were approximately uniform with depth; (4) the measured tensile ; strains at the connection in all sections were small; and (5) secondary reinforcements reduced the maximum tensile strains in the ; primary geogrids.
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• Format:
  PDF
• Funding:
  C1968
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/29651/dot_29651_DS1.pdf
• File Type:
  [PDF - 1.81 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:3a0d771cb94d23c6d2375314ee23b775e51a2b5ef6e716e05f42308f467c138a