GNE-0800 L-01 Modulus Test Results_11-18-11
Delivering the Geopier Foundation System
November 18, 2011 GNE-00800
Robert Egan
R.P. Masiello Inc.
38 Main Street
P.O. Box 742
Boylston, MA 10505
Subject: Geopier Modulus Test Results
Atwood Drive Office Building, Northampton, MA
Dear Bob,
This letter transmits the results of our Geopier® modulus test performed at the Atwood Drive Office Building,
Northampton, MA. The test pier was installed approximately between piers 249 and 254 at grid location D.2-4.8
corner and close to boring B-7. Test pier installation characteristics are summarized as follows:
Top of pier depth below grade, ft.: 2.5 ft.
Pier shaft length, ft.: 20.8 ft.
Pier diameter, in.: 20.8
Shaft Construction (Pull distance / Ram Distance, ft) Pull 4 ft, Ram 3 ft. in silt/clay
Pier Shaft Volume, cf 65.7cf
Grout Mix – Water:Cement 7.5 gal to one 94 lb bag of concrete
Grout Cutoff Depth / Grouted Shaft Length, ft. 9 ft., 14 ft. Grouted Shaft
Grout Volume, gal / cf 39 gal. / 5.2 cf
Bottom Stabilization Performance Test results (BST-P) 1/2 in. in 3 minutes at 21 ft.
A test pier installation log and plot of the test results are attached to this letter. The test results indicate a top of pier
deflection of 0.074 in. and a bottom of pier deflection of 0.014 in. at design stress. In addition, test data indicates a
Geopier Stiffness Modulus (Kg) of 2,611 pci at 100% of the design top-of-Geopier stress of 27.82 ksf. This test
value exceeds the design Geopier Stiffness Modulus of 275 pci, thereby indicating acceptable results.
As a result of this test, Helical Drilling, Inc. may complete construction of production piers for the remainder of the
project using the materials and construction procedures that were used to construct the successful test pier. In the
meantime, please do not hesitate to contact us if you have any further questions.
Sincerely,
DESIGN/BUILD GEOTECHNICAL, LLC
James R. Wheeler, PE
Principal
Attachments: Impact Pier Modulus Load Test Summary
cc: Chad Graybill (HDI) – via email Bernie Dickson (Dickson & Burlingame) – via email
Doug Mattoon (Associated Builders) – via email Mike Pockoski (GFC) – via email