Abstract: A trench liner system used for forming a single or a dual containment trench where expansion and contraction of the liner is controlled. For single containment, the trench system has a primary liner or a primary liner and a separator. For dual containment, the trench system has a primary liner and a secondary liner, or a primary liner, a separator and a secondary liner. Each system also includes anchors spaced along the length of the liner so as to partition the liner into juxtaposed vertical segments. The anchors allow unimpeded contraction and expansion of the liner between anchors within a segment. These embodiments may include a holding element for holding the liners against the trench walls so as to allow each segment to expand and contract along its respective length. Another embodiment of this invention provides laterally extending cavities spaced along the length of the trench.

Abstract: A trench liner system used for forming a single or a dual containment trench where expansion and contraction of the liner is controlled. For single containment, the trench system has a primary liner or a primary liner and a separator. For dual containment, the trench system has a primary liner and a secondary liner, or a primary liner, a separator and a secondary liner. Each system also includes anchors spaced along the length of the liner so as to partition the liner into juxtaposed vertical segments. The anchors allow unimpeded contraction and expansion of the liner between anchors within a segment. These embodiments may include a holding element for holding the liners against the trench walls so as to allow each segment to expand and contract along its respective length. Another embodiment of this invention provides laterally extending cavities spaced along the length of the trench.

Abstract: A flexible trench liner system used for forming a single or a dual containment trench where during a trench overflow, the liquid run-off is prevented from migrating behind the primary flexible liner or behind the secondary flexible liner and possibly leaking onto the trench walls and bottom. The system includes an upper portion on the flexible liner means that overlaps at least a portion of the bearing surface of the trench. The overlapping upper portion of the flexible liner can be part of the primary liner and/or the secondary liner. The flexible liner means are held against the trench walls and the bearing surface by a holding means.

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.

Abstract: A method and apparatus for forming a trench with grates or solid covers comprising an outer shell which is disposed between opposed frame members at a certain position, within a ditch and an inner core that is received within a channel in the shell. The core aids in providing rigidity to the shell while concrete hardens about the outer surface of the shell. After the concrete or other encasing material sets, the core can be removed from the shell which then enables the shell to be more easily displaced from the formed trench. One end of a core can project outwardly from an end of its shell so as to be received within the space formed in the rear of the channel of an abutting shell which, likewise, has its core projecting beyond its front end wall, thereby helping to align the shells within the trench.

Abstract: A method and apparatus for forming a trench with grates or solid covers, comprising an outer shell which is disposed between opposed frame members at a certain position within a ditch and an inner core that is received within a channel in the shell. The core aids in providing rigidity to the shell while concrete hardens about the outer surface of the shell. Rods are vertically driven through the core and the outer shell into the bottom of the trench to stabilize the forms while the concrete or other setting material is poured into the trench. The rods are removed before the material hardens. After the encasing material sets, the core can be removed from the shell which then enables the shell to be more easily displaced from the formed trench.

Abstract: A system for forming a multi-walled trench comprising an outer wall, an inner wall disposed within the outer wall and along which the fluid to be contained flows, means for securing in position the inner wall so as to allow expansion and contraction thereof relative to the outer wall and means for vertically adjusting the trench relative to the surface elevation prior to the pouring of concrete. Various embodiments of the securing means are provided.

Abstract: A system for forming a multi-walled trench comprising a pair of frame members, each having a horizontal section and a section depending from the horizontal section; a holding pan having sidewalls exterior to the depending portion of the frame members, a bottom floor disposed between the sidewalls, and flanges on each sidewall extending parallel to the plane of the horizontal section of the frame member and away from the depending portion; an outer wall disposed within the holding pan having an inside surface and an outside surface, the outside surface of the outer wall engaging at least a portion of the sidewalls and the bottom walls of the holding pan; an inner wall disposed within the outer wall having an inside surface and an outside surface, the inside surface of the inner wall engaging at least a portion of the inner surface of the depending portion of the frame members, and a cavity being formed between the outside surface of the inner wall and the inside surface of the outer wall; means in the cavity f

Abstract: A device for forming a trench having a pair of frame members each having a first adjustment slot therethrough, a form pan having sidewalls, the sidewalls having an adjustment slot in registration with the first adjustment slot of the frame members, and means for adjustably securing the form pan to the frames through the first and second adjustment slots to allow positioning of the form pan relative to the frames.

Abstract: A device for forming a trench having a pair of frame members, connecting rods disposed between the frame members to maintain the frame members in a fixed position relative to each other, anchoring means attached to the frame members for positioning the frame members relative to the ground and a form removably held in a fixed position between the frame members having an upper surface and a shaped lower surface, the shaped lower surface providing means for molding a moldable trench composition into the shape.

Abstract: A method and apparatus for constructing a grate or solid covered trench is provided, having a "Z" type frame made positionally adjustable by an adjustment slot and fastening means combination, and a trench-form construction achieving stability by means of a number of box-shaped bracings positioned along the trench-form sidewalls. The positions of the bracings are staggered to provide both a supporting surface to the frame and stability to the lower regions of the sidewalls.