Advancing tunnel supporting framework - has hydraulic vertically adjustable columns coupled together by horizontal beams under roof

摘要

The structure comprises four coupled frames each with two columns located on the gallery face. The columns are connected to the transverse beams via a hinge coupling. Two of the frames are connected together to the one frame combination by top traverses and mechanically extendable spacers while the other two frames are similarly connected by further top traverses and spacers. Each of the two top traverses consist of two double jointed sections. When viewed in plan view the parallel rows of traverses are arranged with two capping sets alternating with one another and displaced longitudinally so that at one end of the structure the tips of one set project forward of those of the other set. The frame combinations can be displaced along the gallery by upper and lower cylinders coupled between them.