M ALCOLM D RILLING C OMPANY I NC . D OWNTOWN S AN F RANCISCO - PowerPoint PPT Presentation

M ALCOLM D RILLING C OMPANY I NC . D OWNTOWN S AN F RANCISCO

Transbay Construction

140ft 181 Fremont 125 ft

Site preparation • Pre Drill to remove existing timber piles • Replace Class 1 contaminated soil with engineering fill.

• 56 Each, 95’ deep cutter soil mix concrete panel • Each has one two or three wide 90’ flange beams • Drilling sequence is very critical due to Primary / Secondary panels 3.3’’ • Tracking large amount of 9.2’ data

• 80ft long sampling beam • Dip into the freshly installed concrete panel and collect sample at various elevation • Sample then cast into cylinders and break at 3/7/14/28 days • Test for both strength and permeability

Splash protection Continuous water spraying to suppress ill odor

Reference Frame, set to precise Checking location to allow Plumbness accurate placement of the Wide Flanges

Wide Flange - Cutting the site in half. Consistently storing 10 – 15 beams on site.

Spoil Pool – Stored on site for 24 hours before it solidifies and ready to be off hauled.

Test Pile – 72” diameter, 263.5’ deep, 28’ into rock The actual test - 22 hours continuous monitoring with max load of 9200 kips

Report of the test shows satisfactory results We now move on to production ! Not so fast… More preparations!

100ft 120 – 130 ft 20+ ft

To do the work we need: And we have: • Bauer BG 46 Rotary Drill Rig 125’ by 140’ … … • Sumitomo 1500 Crawler Crane • Leffer 2.5m Casing Oscillator • Oscillator Power Pack • 120 LF of 6’ diameter double wall casing • 270 LF of 5’ diameter rebar cage, 1 per pile • Air Compressor • 7 each - 20,000 gal Baker Tanks • Boom Concrete Pump • Excavator and Loader • Concrete Trucks • Off Haul dump trucks

Site Reconfiguration – Disintegrate the scaffold Move all baker tanks to a different location to make access for drilling operation for the remaining piles.

Pile installation procedure: • Set up over a pile and drill the top 5-10’ • Start twisting casing using oscillator and charge the hole with polymer slurry • Continue drilling while adding more casing (20’ section each time until 100+’ of casing BGS) • Continue drilling down to top of rock (rock verified by Geotechnical engineer on site) • Drill 20’ of rock socket • Do a complete water exchange to remove all suspended solid • Pick / splice / set rebar cages (260+’ cage came in four 60+’ pieces) • Pour concrete • Conduct Crosshole Sonic Log on each pile upon completion

Fresh slurry going into the hole Dirty slurry coming out of the hole

Me, measuring cages These are for 1 pile

Color coding the verticals to make sure they can splice properly.

Remember this guy? That’s our test pile ! Its about 15 mins since you saw it the last time, for us at that time was a year!

• Put in lot of effort in pre planning will help you succeed in a complex job like this • Team work is very important. Good communicated between the members of the team will help the job go smooth • Track every detail, adjust accordingly • Experience is very important, but for job like this, hardly anyone will have the experience. Hence, being knowledgeable and able to react quickly to problems is essential.