The Mechanics of Flexible Liners

• Published in: Hydrologic Measurements with Flexible Liners and Other Applications Vol. 1; pp. 7 - 42
• Main Author: Keller, Carl
• Format: Book Chapter
• Language: English
• Published: United Kingdom CRC Press 2023; Taylor & Francis Group
• Edition: 1
• Subjects: Heavy Mud; Mud Density; Excess Head; Open Hole; Grout Fill; Liner Installation; Liner Inversion; Surface Casing; Artesian Head; Water Table; Vent Tube; WT; Water Level; Borehole Wall; Hole Wall; Towing Force; Highest Head; Inverted Liner; Air Canister; Artesian Condition; Liner Seal; Inverted End; Open Borehole; Flexible Liner; Deep Water Tables
• ISBN: 1032212624; 1032214279; 9781032212623; 9781032214276
• DOI: 10.1201/9781003268376-3

This chapter describes the mechanics of flexible liners including the magnitude of the towing force of an everting liner, the effect of drag, hole diameter, wet film adhesion, trapped air in the liner, and the effect of borehole breakouts on liner version. Liner removal methods and the hazards are explained, and the influence or formation conductivity on the eversion process is described. Liner seal quality and the influential factors are explained. Numerous installation devices are described. This chapter describes the mechanics of flexible liners including the magnitude of the towing force of an everting liner, the effect of drag, hole diameter, wet film adhesion, trapped air in the liner, and the effect of borehole breakouts on liner version. It is an explanation of the mechanical aspects of flexible liners. There are many kinds of flexible liners. Some of the most useful are strong and flexible and were originally constructed from urethane-coated nylon fabrics. A very simple technique for determination of the highest head in the formation uses the flexible liner emplaced in the borehole. It has been observed that a grout fill of the liner will often raise the pH of water outside of the liner and can affect the pH of water samples.