Description

Send Inquiry

Self-drilling anchors are the advanced type of fully threaded hollow steel tube rods. SDA is a fully threaded rod with an inner and outer diameter hollow steel tube. It is provided with a sacrificial drill bit at the end to facilitate the drilling process, coupler to join two SDA bars, screw nut, base plate, etc. The hollow steel tube has one side sacrificial drill bit and, at another end, tied with nut and steel base plate. A hollow steel tube is placed in the center of the drill hole using a centralizer to maintain its position. The grout, which covers the SDA periphery, protects the SDA under aggressive environment conditions with simultaneous grout ground and grout bar interaction throughout the threaded bond length. Self-drilling sacrificial drill varies based on the rock or soil conditions.

The hollow steel tube has more bending strength and more circumference area compared to the solid steel bar (soil nail) with the same cross-sectional area. Due to these benefits of self-drilling anchor, it has advantages over other for reinforcing solid bars, soil nails, and rock anchors. SDA installation can be done by a small drilling machine that can move in difficult access areas and provide slope protection work in difficult reach. Its application, not just only application to soil and slope reinforcement, but also for tunnel application like forepoling for tunnel advancement.

Components of SDA

● Drill Bit

One of the main components in this technology is a sacrificial drill bit. It helps the drilling and inserting of SDA operation at the same time. This increases the productivity of the SDA installation. The sacrificial drill bit quality defines improving the SDA technique's penetration rate, performance, and cost-efficiency.

● Hollow Anchor Bar

The rolling process enhances the yield strength of the steel. The fully threaded hollow bar allows drilling using a sacrificial drill bit at one end and another end to connect to the standard drill tool that works simultaneously for drilling and grouting. Full threading length of SDA makes it more beneficial to grate bonding to grout and tube and enable for drill rig connections and couplings.

● Coupler

The couplers' main aim is to provide the connection between seating of each hollow tube face-to-face connection. This is the main component for the energy transmission from end to end connection of anchor and provides maximum percussive energy to drill bit with lesser losses.

● Plate

Bearing plate with sufficient thickness of steel plates having a central hole required at the face of SDA. The main function of this plate is to transfer the tension load of SDA to the ground.

● Nut

The hexagonal nuts are made of high strength steel with properly made by all edges to satisfy the demands of anchor specifications and other operations.

● Centralizer

Centralizers are used to centre the hollow bars within the borehole and to ensure the correct grout cover of the load-bearing element according to the relevant standards and as specified in the approvals.

Application

● Slope stabilization

Self-Drilling Anchors are very suitable for weathered or un-consolidated rock stabilization. This technique is a more superior form of stabilization because the SDA technique is a relatively easy and fast method of installation compared to the outdated methods.

● Foundations with micro piles

SDAs can be used like monopoles and micropile types because these are drilled piles composed of steel reinforcement with injected grout. These anchors are used like micropile type to stabilize the ground and related foundation problems. These anchors are suitable for tension and compression loads at varying ground conditions.

● Tunneling

Self-drilling anchors are most suitable for the stabilization of tunnel strengthening works. Mostly for the soft rock and overburden soil conditions, the SDA's are apt for rooftop protection.

Specification

Drill bit type

DRILL EITS
Bit shap
Bit type	Clay Bit	XX	EX	EC	ES-F	ES-D	EY	EYY	ECC	EXX	ESS-F

Performance

• Nut(Hex/Dome)

Description	R32	R38	R51	T51	T76	T103	T108	Unit
Key size	46	50	75	100	100	125	125	mm
Length	45	60	70	80	80	80	80	mm
Weight	0.4	0.5	1.6	2.7	2.4	2.9	3.1	kg

• Coupler

NO.	Adaptable Bolt	Outer Dia. mm	Length mm	Hardness HRC	Weight kg	Steel Type	Thread Type L/R Hand
1	T30	38	105	25-30	0.45	EN10083-1=4140=42CrMo	L/R
2	T40	54	140	25-30	1.20
3	T52	70	160	25-30	2.30
4	T73	95	235	25-30	4.30
5	T76N	95	200	25-30	4.30
6	T76S	97	220	25-30	5.40
7	T103	123	255	25-30	7.45
8	T108	130	220	25-30	7.4

• Centralizer

No.	Outer Dia. mm	Length mm	Hole Dia mm	Steel Type	Weight kg
1	68	35	35	CK45	0.35
2	70	35	40		0.36
3	85	40	52		0.52
4	95	40	67		0.53
5	125	40	67		0.86
6	140	50	80		1.25
7	170	60	112		2.15
8	65	35	35		0.30
9	70	35	40		0.36
10	85	40	53		0.52
11	103	60	150		1.4
12	110	50	80		0.75
13	140	60	112		1.25
14	150	60	108		1.62

• Hollow Anchor Bar

NO.	Surface Treatment	Outer Dia. mm	Inner Dia. mm	Weight k/mg	Steel Type	Thread Type L/R Hand	Ultimate Load KN	Yield Load KN	Part Number
NO.	Surface Treatment	Outer Dia. mm	Inner Dia. mm	Weight k/mg	Steel Type	Thread Type L/R Hand	Ultimate Load KN	Yield Load KN	Part Number
1	Epoxy Coating or Hot-dipped Galvanization	25	14	2.30	EN10083-1=4140=42CrMo	L/R	200	150	R25N-14
2		32	21	2.90			280	230	R32N-21
3			18.5	3.40			280	230	R32N-18.5
4			16	3.60			360	280	R32S-16
5			15.5	3.80			405	350	R32SS-15.5
6		38	19	5.50			500	400	R38N-19
7		38	21	4.80			500	400	R38N-21
8		51	36	7.00			550	450	R51L-36
9		51	33	8.40			800	630	R51N-33
10		30	11	3.41			320	260	T30-11
11			14	2.87			275	220	T30-14
12			16	2.70			245	190	T30-16
13		40	16	6.60			660	525	T40-16
14		40	20	5.60			540	425	T40-20
15		52	26	9.87			925	730	T52-26
16		64	44	11.60			1042	900	RR64-44
17		73	53	14.10			1160	970	T73-53
18			56	10.75			1035	830	T73-56
19			45	17.80			1585	1270	T73-45
20			35	21.20			1865	1430	T73-35
21		76	45	15.00			1900	1500	T76S-45
22			51	19.70			1600	1200	T76N-51
23			54	15.80			1620	1220	RR76-54
24		103	78	25.30			2270	1800	T103-78
25		103	51	44.60			3660	2670	T103-51
26		108	82	27.90			2580	1980	RR108-82
27		111	82	25.00			2640	2000	T111L-82
28		111	75	34.50			3650	2750	T111N-75
29		127	111	28.90			2320	2030	T127-111
30		130	60	75.00			7940	5250	T130-60

• Plate

No.	Adaptable Boilt	Size mm	Thickness mm	Hole Dia mm	Weight kg	Steel Type
1	R25N	150*150	8	30	1.40	Q235B
2	R32L/R32N	200*200	10	35	3.00
3	R32S/R32SS	200*200	12	35	3.70
4	38N	200*200	12	41	3.60
5	51L	200*200	30	60	8.80
6	51N	200*200	40	60	18.50
7	T30	200*200	8	36	2.45
8	T40	200*200	12	54	3.50
9	T52	220*220	35	65	12.15
10	T73	250*250	40	80	18.50
11	T76N/T76S	250*250	40	80	19.50
12	T103	300*300	50	110	33.00