Ring bit Tunnel Forepoling Casing Advance

Forepoling, also known as tube umbrella, is an application used to strengthen tunnel roof in broken rock conditions. Drilling system consists of casing tubes which are drilled through the overburden as an umbrella and filled with grouting. KAT Casing System allows easy driving of the casing tubes into the ground with low torque demand. In modern forepoling also fibreglass casings can be used for ultra-long facebolts.

KAT Casing Systems mostly used in forepoling are RoX+ 88,9/8, RoX 114,3/10 and RoX 139,7/10.

Casing tubes

Typically one pile consist of several steel casings of 1,5 – 3 meters

Connection by thread

Injection valves for grouting

Standard casing diameters: 88,9 – 114,3 – 139,7 – 168,3 mm

. Pilot Bits . Ring Assemblies . Drill Rods . Starter Casings . Extension Casings . Grouting Plugs (end caps) . Adapters . Grouting Valves . Forepoling Drilling Systems

System code	Casing				Ring bit				Pilot bit		Thread
	[mm]	[in]	[mm]	[in]	[mm]	[in]	[mm]	[in]	[mm]	[in]
RoX+ 76,1/4	76.1	3	4	0.157	52	2.047	90	3.543	66	2.598	R32
RoX+ 76,1/8	76.1	3	8	0.315	47	1.850	90	3.543	59	2.323	R32
RoX+ 88,9/4	88.9	3 ½	4	0.157	71	2.795	99	3.898	80	3.150	T38
RoX+ 88,9/8	88.9	3 ½	8	0.315	50.8	2.000	94.9	3.736	70	2.756	T38
RoX+ 101,6/10	101.6	4	10	0.394	65	2.559	110	4.331	79	3.110	T38
RoX+ 114,3/5	114.3	4 ½	5	0.197	91	3.583	128	5.039	102	4.016	T38
RoX 114,3/10	114.3	4 ½	10	0.394	73.5	2.894	120.30	4.736	92.5	3.642	T38
RoX 139,7/10	139.7	5 ½	10	0.394	94	3.701	145.70	5.736	117.5	4.626	T45
RoX+ 159,0/10	159.0	6 ¼	10	0.394	119	4.685	169.0	6.654	137	5.394	T45
RoX+ 168,3/10	168.3	6 ⅝	10	0.394	127	5.000	182.3	7.177	147	5.787	T45
RoX+ 219,1/12,7	219.1	8 ⅝	127	0.500	167	6.575	234	9.213	191	7.520	T45
RoX+ GFRP 76,1/8	76.1	3	8	0.315	47	1.850	90	3.543	59	2.323	R32
RoX+ GFRP 76,1/8	76.1	3	8	0.315	47	1.850	90	3.543	59	2.323	T35