BOREMAC Pressuremeter Manual

INSTRUCTION MANUAL SELF-BORING PRESSUREMETER Model BOREMAC ? Roctest Limited, 2011. All rights reserved. This product should be installed and operated by qualified personnel only. Its misuse is potentially dangerous. The Company makes no warranty as to the information furnished in this manual, and assumes no liability for damages resulting from the installation or use of this product. The information herein is subject to change without notification. Tel.: 1.450.465.1113 • 1.877.ROCTEST (Canada, USA) • 33 (1) 64.06.40.80 (Europe) • www.roctest-group.com E10061-31052011 i TABLE OF CONTENTS 1 INTRODUCTION...................................................................................................... 1 2 DESCRIPTION OF THE BOREMAC COMPONENTS ............................................. 1 2.1 The Disintegrator Module .................................................................................. 1 2.2 The Probe ......................................................................................................... 1 2.3 The Probe to Rod Adapter ................................................................................ 2 2.4 The Rod String .................................................................................................. 2 2.5 The Disintegrator Drive Unit .............................................................................. 2 2.6 The Water Swivel .............................................................................................. 3 3 SYSTEM ASSEMBLY ............................................................................................. 3 4 SETTING THE PROBE IN PLACE .......................................................................... 3 4.1 Self-Boring ........................................................................................................ 4 4.2 Test Execution .................................................................................................. 4 5 ASSEMBLING A NEW SHEATH ............................................................................. 5 E10061-31052011 BCD Page 1 1 INTRODUCTION The Boremac self-boring pressuremeter can be used with either a TEXAM of a GAM-ll pressuremeter. The only difference between using one of these pressuremeters’ probe alone or in conjunction with the Boremac components resides in the method the probe is set in place. The execution of the test itself remains the same and is fully described in the TEXAM or G-AM-ll pressuremeter instruction manual. Maximum working pressure in the self-boring mode is 4000 kPa (600 PSI). 2 DESCRIPTION OF THE BOREMAC COMPONENTS The Boremac is comprised of: - A disintegrator module - A modified TEXAM/G-AM, N size probe - An EW to probe adapter - A coaxial rod string - The disintegrator drive unit - A water swivel 2.1 THE DISINTEGRATOR MODULE The disintegrator module consists of the following components: - A 68 mm O.D. by 126 mm-long threaded cutting shoe. - A 275 mm-long cylindrical housing containing the lower guide for the inner disintegrator rod. - A helicoidal 4-wing cutter, 2 wings of which are fitted with hardened steel pin teeth. Two holes through the cutter allow the passage of water. The cutter is threaded onto a hollow rod 16 mm in diameter and 152.4 cm in length. 2.2 THE PROBE The probe is similar to the N size TEXAM or G-AM probe with the exception of the external metallic tapered rings and nut assemblies which lock the tapered rings in place. The tapered rings are made of cadmium plated steel and have the same outside diameter as the cutting shoe. The rings are advanced and held in place by an internal 61 mm O.D., 12.5 mm wide knurled nut which threads onto the core of the probe. An external nut with a 68 mm O.D. and 28 mm width fits over the knurled nut and threads onto the outer threaded male extremity of the tapered ring. E10061-31052011 BCD Page 2 2.3 THE PROBE TO ROD ADAPTER The adapter is comprised of 2 parts: - A 27.5 mm long cylinder with a uniform OD which screws onto the probe. The cylinder houses the tubing connection to the probe. It has 6 countersunk holes to accept the screws which hold the upper and lower parts of the adapter together. - A grooved adapter 25 cm in length which slides flush into the top end of the lower part of the connector. It is held in place with 6 countersunk machine screws. The longitudinal grooves in this part allow the spent drilling fluid to the surface as well as the passage of the tubing linking the control unit to the probe. 2.4 THE ROD STRING The coaxial rod string is comprised of: - An outer EW casing string 46 mm OD assembled in 1.52 m lengths. The EW casing is used to transmit thrust to the probe as well as to extract the probe. - An inner 22.2 mm OD by 9.5 mm ID rod string threaded and flush coupled in 1.52 m lengths. 2.5 THE DISINTEGRATOR DRIVE UNIT This unit is comprised of an hydraulic motor coupled to a gear reducer which rotates the inner rods. The specifications for the hydraulic motor are as follows: Displacement : 49 cm3 (3 in.3)/rotation Maximum speed : 885 RPM Maximum flow : 45 liters/min. (11.9 US gpm) Maximum torque : 83 Nm (873 lb. in.) Working pressure: 10,003 kPa (1500 psi) Maximum allowable pressure : 15,500 kPa (2250 psi) E10061-31052011 BCD Page 3 2.6 THE WATER SWIVEL The water swivel threads onto the uppermost end of the inner rod string. It is fitted with a straight male 12.5 mm tubing connector to accept the 10 mm ID flexible tubing which feeds water to the inner rod string. 3 SYSTEM ASSEMBLY - Thread from top to bottom the coaxial tubing, which links the pressuremeter to the probe, through the lower plain cylindrical part of the probe to rod adapter. - Saturate the probe as described in the TEXAM / G-AM instruction manual. - Screw the lower part of the probe to rod adapter onto the upper extremity of the probe. - Connect the upper slotted component of the 2 part rod adapter to its mating part using the 6 countersunk screws. The tubing will occupy one of the longitudinal slots. - Thread the 5 foot long lowermost inner rod through the probe assembly. - Thread the locking nut and cutter onto the lower end of this rod. - Screw the cutting shoe onto the cylindrical probe extension which houses the inner rod guide. - Screw the above 2 part assembly onto the threaded lower end of the N probe. 4 SETTING THE PROBE IN PLACE - Open a 1.5 meter (5 foot) length, 76 mm (3 in.) diameter pilot hole. Slowly lower the probe into this hole being careful not to plug the lower extremity (especially in soft materials). - Assemble through the drill head a sufficient number of coaxial rods to the top of the probe so that the latter protrude beyond the top of the drill head. Tighten the chuck on the outer EW casing in the same manner used for any rod string. Place the rotation control valve in the locked position so as to PREVENT ANY ROTATION of the outer EW casing. - Place the cutter drive unit over the top end of the rod string protruding from the drill head. Fit the female lower end of the drive unit unto the EW casing and tighten the lock bolt locking the drive unit in place on the EW casing. - Adjust the position of the cutter blade as required by soil conditions. For stiffer soils, the cutter will exceed the leading edge of the cutting shoe. Proceed as follows: First, determine the position of the cutter by raising the inner rod string until the cutter butts against the rod guide within the lower part of the disintegrator module. In this uppermost position, the lower blade of the cutter is located inside the shoe about 20 mm above its tapered leading edge. This distance must be E10061-31052011 BCD Page 4 precisely measured in advance. Next by measuring the distance rod is lowered, it is a simple matter to calculate the position of the base of the cutter with respect to the leading edge of the cutting shoe. Finally, lock the cutter in position using the two machine screws located on the cutter drive unit. - Install the water swivel on inner rod and connect the 12.5 mm flexible tubing to the water pump. - Connect the hydraulic motor to its power supply. Be careful to observe the flow direction requirements to obtain the correct direction of cutter rotation. 4.1 SELF-BORING - The different parameters for self-boring vary according to the soil type encountered. The soil should be GRAVEL FREE and homogeneous. - The speed of rotation should be between 50 and 300 RPM (eg 100 RPM in clay). The penetration rate will be between 10 cm/mn and 50 cm/mn (eg 30 cm/mn in clay) and should be very regular. - The drilling fluid pump should be capable of supplying 15 l/mn (4 US gpm). - During the self-boring, the flow of drilling fluid should be maintained constant so as to provide a regular return of fluid. An excessively high flow will result in an oversize hole. - Turn the flow of drilling fluid on and wait until there is a return of drilling fluid to the surface. - Begin the rod rotation. - Proceed with the downward penetration of the probe. Checking the probe penetration rate and the rate of drilling fluid return. - When the end of the stroke is reached or the testing depth is attained: - Stop probe penetration - Stop the rod rotation - Maintain drilling flow for approximately 1 minute and then cut the flow off. - Remove the cutter drive unit as described above. 4.2 TEST EXECUTION Procced as described in the TEXAM / GAM-ll instruction manual. E10061-31052011 BCD Page 5 5 ASSEMBLING A NEW SHEATH Screw the probe to vice adaptor andclamp the adaptor in a bench vice. Place the pair of o-rings in their grooves. Slide the outer protective sheath over the probe’s body. Center the sheath with respect to the o-rings. Use three screw clamps for preventing the sheath from moving. Non-petrolium molykotelubricant may be used sparringly to assist in mounting the sheath. Slide the tapered sleeves in place over the ends of the sheath. Orient tapered sleeve such that the threaded extremity points outward. Screw on the brass knorled nuts to the body of the probe. This will advance the outer tapered sleeves inward providing a seal between the sheath and the o-rings. Continue to advance the brass nuts untill approximately 19 mm of thread is exposed beyond the nuts. When advancing the nuts, verify that norelative movement between the sheath and the probe’s body occurs. This can be achieved by holding the sheath in position with three crew clamps. Then, screw the cover nut unto the tapered sleeve. The dissassembly is done following the same steps in a reverse order. The metallic rings can be sligthly warmed to facilitate their removal.