关键词: 管廊节段, 长线法, 匹配预制, 拼装

Abstract: There are several challenges in the longline matching prefabrication and assembly process of multicabin utility tunnel segments with large crosssections. These challenges include the prefabrication of end segments, internal mold design and separation technology of the large crosssection multicabin utility tunnel segments, positioning accuracy control of the reserved holes and embedded parts in the tunnels, and alignment control and rectifying technology of the segment under the condition of a large longitudinal installation slope. To address these issues, the characteristics and key points of this technology are analyzed and studied in detail based on a utility tunnel project of Meishan Road, Ring East Sea area, Xiamen. Through a field application test and engineering practice, the following corresponding technical schemes are proposed. (1) The technology of binding and integral hoisting is used in the end segment, and a hollow rubber plug and rubber strip are developed for positioning the exposed reinforcement and steelplate waterstop. (2) The adjacent tunnel segments are separated using hydraulic push technology. Moreover, to reduce the friction resistance of hydraulic jacking, a straw or thin fiber board is used to separate the tunnel segments from the concrete mould. (3) The split joint structure of the formwork is vertical, and a hydraulic drive system is used to control the automatic movement and the opening and closing of the side panel of the internal mold. (4) The positioning hole is established in the corresponding position of the formwork, and the quality of the embedded technology is improved by studying and fabricating the silica gel rod and rubber parts. (5) By measuring the central axis and horizontal line marked in the tunnel segment, the control of the tunnel segment alignment is realized; in outoftolerance cases, a singleside support pad of epoxy resin is used for alignment adjustment. Under the working condition of a large longitudinal slope, a custommade variablefrequency door machine with threedirectional fine tuning is used to assemble the segment. Results indicate that the technical scheme yields good results and economic benefits in practical applications. Moreover, the proposed scheme is successfully applied to a utility tunnel project of Xiang′an East Road in Xiamen.

Key words: utility tunnel segment, longline method, matching prefabrication, assembly