LEFFER
STAHLBAU - APPARATE- UND MASCHINENBAU - LEICHTBAU - MONTAGEN
Stahl- und Apparatebau Hans Leffer GmbH & Co. KG
⋅
Postfach 20 03 60
⋅
66044 Saarbrücken
Ust-IdNr.:DE 814736552
40-010137
Hausanschrift:
Telefon
+49
-
6897-793-0
Bankverbindungen:
Pfählerstraße 1, Dudweiler, 66125 Saarbrücken / Deutschland
Telefax
+49-6897-793 330
Landesbank Saar Girozentrale, Saarbrücken
+49-6897-793 217
Nr. 5182-001
(BLZ 590 500 00)
Briefanschrift:
Bayerische Hypo- und Vereinsbank AG, Mannheim
Postfach 20 03 60, 66044 Saarbrücken / Deutschland
Nr. 7 002 580
(BLZ 670 201 90)
Express-Station:
Handelsregister Saarbrücken HRB 4398
Geschäftsführer: Hans G. Leffer, Georg Leffer
Hauptbahnhof, 66111 Saarbrücken / Deutschland
38
L
H
8.4.5
Excavation by means of a drilling rig or a hammer grab is effected continually.
Depending on the hardness of the soil, excavating should be started, after the casing
has been driven down approx. 2 – 3 m – 6´ 6” – 10’.
The drive down/pull back movement (pumping action) will loosen the soil, so that
the tools used for excavation can easily penetrate.
8.4.6
Install the 2
nd
casing and continue as described before.
8.4.7
As soon as the cutting shoe of the starter casing hits hard rock, proceed in accordance
with drawing no. 4.46690.
8.5 SPECIAL INSTRUCTIONS
8.5.1
Do not try to form a core of more than 200 mm ~ 8” without excavating.
This will only cause a high torque, unnecessary wear and tear, high temperatures and
fuel consumption without increasing the drilling progress.
8.5.2
During drilling, try to release as much cuttings as possible, accumulated between
casing wall and rock wall.
8.5.3
When driving down the casings, do not exceed 200 bar – 2900 psi for oscillating.
Otherwise it may become impossible to extract the casings after concreting.
8.5.4
When driving down the casings, using oscillating rapid motion, do not exceed an
oscillating pressure of approx. 150 bar – 2175 psi as indicated on the hydraulic
pressure gauge.
If a higher oscillating pressure than 150 bar – 2175 psi must be used, switch off the
rapid motion!
