Base Mat Assembly And Method For Constructing The Same

Abstract

A precast reinforced concrete base mat element, a base mat assembly and method for constructing a base mat assembly from a plurality of the base mat elements are described. The base mat element comprises a concrete body having first and second conduits extending there through in first and second generally perpendicular directions and a liner plate anchored in the concrete body. Preferably the concrete bodies have interlocking surfaces formed there on. A plurality of the base mat elements may be juxtaposed together with the interlocking surfaces interlocking with one another and with the tensile members extending through the first and second tensile conduits and being post-tensioned and anchored about the base mat elements to clamp the base mat elements together. The liner plates may then be welded together to form a generally planar membrane. In one embodiment, at least one of the first and second tensile conduits is located above and one below the horizontal center planes of the concrete bodies to limit the base mat elements from displacing vertically relative to one another.

Description

TECHNICAL FIELD[0001]The present invention relates generally to LNG (liquefied natural gas) tanks and methods for constructing LNG tanks, and more particularly, to base mat foundations for containment tanks which are used to support LNG tanks.BACKGROUND[0002]LNG full containment tanks typically comprise an inner primary container (hereinafter “inner tank”) for storing LNG and an outer container (hereinafter “outer tank”) which is designed to contain leaks from the inner tank. Large storage tanks, such as those used with LNG full containment tanks, are typically sensitive to differential settlement in the foundations supporting the inner tank which stores LNG. Consequently, standard practice is to build a rigid foundation with a flat top surface supporting the bottom of the inner tank. For example, the foundation can be a grade supported reinforced concrete mat, a deep foundation with a mat resting on the ground, or an elevated slab foundation. In cases where very stiff soil or soft ...

AI Technical Summary

Benefits of technology

[0006]A precast reinforced concrete base mat element, a base mat assembly or foundation and method for constructing a base mat assembly from a plurality of the base mat elements are described. The base mat element comprises a liner plate and concrete body having first an...

Problems solved by technology

Large storage tanks, such as those used with LNG full containment tanks, are typically sensitive to differential settlement in the foundations supporting the inner tank which stores LNG.

However, application of precast elements in LNG tank foundations is not a conventional approach.

Such foundations would be subject to high forces at connections which makes design and construction of such connections very difficult.

It is challenging to provide sufficient vertical stiffness to precast base mat elements forming a base mat while keeping the thickness of the base mats within an economically acceptable range.

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