Installation and Filling-Rofirm Gabions & Mattresses Co.

After the foundation has been prepared, the pre-assembled
gabions shall be placed in position empty, and tied or fastened to adjacent gabion units along all edges in order to form a continuously connected, monolithic structural unit (Figure 8).
Rocks for the gabions may be produced by any suitable quarrying method, and by the use of any device that yields the required sizes within the gradation limits chosen. Rocks shall be hard, angular to round, durable and of such quality that they shall not disintegrate on exposure to water or weathering during the life of the structure.

		Rocks shall range between 100 mm and 200 mm. The range in sizes may allow for a variation of 5% oversize and/or 5% undersize rock, provided it is not placed on the exposed surface. In all cases, the oversize rock shall not be larger than 250 mm, and the undersize rock shall not be smaller than 50 mm. Rock shall be placed in 300 mm lifts for 1 m high gabion units, and 250 mm for 0,5 m high units. The fill layer shall never be more than 300 mm higher than any adjoining cell (Figure 7).

Care shall be taken when placing the stone to ensure that the PVC coating of the wire is not damaged. After a layer of rock has been placed in the cell, sufficient hand manipulation of the rock shall be performed to minimize voids and achieve a maximum density of the rock in the gabion. The rock in exposed vertical faces shall be hand placed to reduce voids in the outer face. Stiffeners or internal cross ties shall be installed connecting the front and back faces of any supported or exposed face at the vertical third points for a 1 m high gabion unit, as the cell is being filled (Figure 5).

Gabion units installed at the wall ends, having two exposed sides, shall also include a set of cross ties installed perpendicularly to the lateral exposed face. For 0,5 m high baskets when used as re vetment, stiffeners or internal cross ties are not required. When more than one vertical layer of gabions is installed, units shall be overfilled to approximately 25 to 40 mm to allow for natural settlement. The top surface shall be smoothly levelled, minimising voids. Ensure that diaphragm tops are easily accessible for connecting.