SLURRY TRENCH STABILITY - THEORETICAL AND PRACTICAL ASPECTS

THIS ARTICLE IS CONCERNED WITH THE PRACTICAL ASPECTS OF A NUMBER OF FACTORS AFFECTING SLURRY TRENCH STABILITY. THE AUTHOR FIRST CONSIDERS MUD PRESSURE, WHICH IS A FUNCTION OF MUD DENSITY (INCLUDING CONTAMINANTS), POINTING OUT THAT THE USE OF WEIGHTED MUDS MAY REMEDY EXCAVATION PROBLEMS, BUT AT THE SAME TIME CAUSE DIFFICULTIES IN CONCRETING. ATTENTION IS DRAWN TO THE RISK OF INSTABILITY FOLLOWING LARGE MUD LOSSES WHEN LOW SAND CONTENT MUDS ARE USED. THE NATURE OF THE MUD CAKE ON THE TRENCH WALLS IS DISCUSSED AND REFERENCE MADE TO THE PERFORMANCE OF DIFFERENT TYPES OF FILTRATION CONTROL AGENTS. THE ARCHING OF SOIL IS NEXT DEALT WITH AND THE IMPORTANCE OF ADEQUATE GUIDE WALLS IN RELATION TO THEIR ROLE AS A TOP ABUTMENT TO THE VERTICAL ARCH IS STRESSED. STABILITY DIFFICULTIES WHICH RESULT FROM PENETRATION OF THE GROUND (VIA FISSURES) AT THE SIDES OF THE PANEL BY THE MUD, ARE DISCUSSED TOGETHER WITH THE LUBRICATION OF POTENTIAL SLIP PLANES AND SWELLING OF THE GROUND. IN CONCLUSION TO THE POSSIBILITY OF TRENCH INSTABILITY IN SALINE CONDITIONS AS A RESULT OF OSMOSIS, NON-SALINE WATER BEING ATTRACTED INTO THE GROUND FORMATION LEADING TO SWELLING OF THE WALLS, INSTABILITY AND CAVING OF THE TRENCH. THE REMEDY GIVEN IS TO ADD SALT OR FCL TO THE MUD.

  • Availability:
  • Corporate Authors:

    Foundation Publications Limited

    7 Ongar Road
    Brentwood CM15 9AU, Essex,   England 
  • Authors:
    • PULLER, M J
  • Publication Date: 1974-9

Media Info

  • Features: Figures; Photos; References; Tables;
  • Pagination: p. 34-56
  • Serial:
    • GROUND ENGINEERING
    • Volume: 7
    • Issue Number: 5
    • Publisher: EMAP CONSTRUCT LIMITED
    • ISSN: 0017-4653

Subject/Index Terms

Filing Info

  • Accession Number: 00083898
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: May 1 1975 12:00AM