Abstract: A trench liner system used for forming a single or dual containment trench comprising a primary liner alone or a primary liner with a secondary liner. In a single containment trench, a primary liner means extends along the length of the trench, and includes a plurality of ribs or pleats spaced laterally along the exterior side of the primary liner, so that the primary liner means is supported within the trench by the ribs or pleats and plurality of cavities are formed between the primary liner means and the trench wall and bottom. For a dual containment trench, the secondary liner means also comprises a plurality of ribs or pleats spaced along the exterior side of the secondary liner, so that the secondary liner means is supported by the ribs or pleats and a plurality of cavities are formed between the secondary liner means and the trench wall and bottom.

Abstract: A trench liner system used for forming a dual containment trench and for relining an existing trench has a primary liner and a secondary liner means extending along the length of the trench, a separating means is disposed between the primary liner and the secondary liner. A means for holding the primary liner, the secondary liner and the separating means against the trench walls has a vertical member having an upper end and an opposite lower end, with a first horizontal member extending from the upper end and terminating in a first edge. A first wall depends from the first edge and a second horizontal member extends from the lower end away from the first horizontal member. The second horizontal member terminates in a second edge having a second wall depending therefrom. The outer surface of the vertical member and the upper surface of the second horizontal member form a ledge adapted to receive grates and covers.

Abstract: A trench liner system used for lining a single containment trench and for forming a dual containment trench from a single containment trench comprising a primary liner means within the trench supported by a separating means between the primary liner and the trench walls and bottom, and a means for holding the primary liner means and the separating means to the trench walls. The separating means comprises a plurality of pairs of elongated members disposed along the trench such that the rear surface of each elongated member is in contact with one wall of the trench and the underside surface of each member is in contact with the bottom of the trench. The elongated members are in opposed relationship to each other. The length of the lower portion of each elongated member is less than one-half the width of the bottom of the trench so that a gap is formed between the distal edges of the lower portions to position therein a means for detecting a leak in the primary liner.

Abstract: A trench liner system used for forming a dual containment trench and for relining an existing trench has a primary liner and a secondary liner means extending along the length of the trench, a separating means is disposed between the primary liner and the secondary liner. A means for holding the primary liner, the secondary liner and the separating means against the trench walls. The separating means also includes a perforated plate in contacting relationship with the lower edges of the opposed elongated members under which a means for detecting a leak in the primary liner is positioned. The separating means has a plurality of ribs spaced between the liner means so that a cavity is formed between the primary liner means and the secondary liner means between the ribs.

Abstract: A system for forming a single-walled trench comprising a pair of frame members, each having a horizontal section and a section depending from the horizontal section; a collapsing pair of wall pans having sidewalls interior to the depending portion of the frame members, a bottom floor disposed between the sidewalls, a releasing mechanism to collapse inward the sidewalls, a device which collapses the sidewalls inward and removes the entire bottom and sidewalls from the poured trench leaving the frames embedded securely in the concrete; and adjustable anchoring means attached to the frame members for providing vertical adjustment of the frame members relative to the ground and each other, leaving all but the frame members available for re-use.