Method and apparatus for in situ forming underground panelized concrete walls with improved joint structure

Abstract

This invention relates to slurry method and apparatus for forming panelized concrete walls with a positive seal between joints. The invention is basically an improvement on the process disclosed in Veder U.S. Pat. No. 3,310,952. The slurry method or process includes the formation of a plurality of overlapping trench sections in the presence of a slurry, typically a thixotropic bentonite, with the overlapping ends between trench sections being maintained open by a hollow tubular pipe member. The joint between the concrete panels include a positive seal member bridging the gap between the adjoining panels. Portions of the positive seal members according to this invention are carried furled or folded in slots in the end stop pipe. Each furled seal portion is comprised of a vertical support bar having sealingly secured thereto a plurality of horizontally extending anchor and seal portions rigidly secured to one surface of the vertical support bar where the concrete is to be poured in a panel section. The furled positive seal member is sealingly coupled to the opposite side of the vertical support bar member and is unrolled or unfurled after the stop pipe has been removed and the next succeeding panel excavation has been performed. In this way, the positive seal remains in a protected position during the excavation for the next panel section and is then unfurled from the protected position into the slurry in the just excavated panel section.

Dependencies are inferred from the claim text.