Page 226 - Villas at Savona Close-out Manual

Geotechnical Investigation Report
Villas at Savona

1.0 INTRODUCTION

This report presents the results of a geotechnical investigation completed by Amec Foster
Wheeler Environment & Infrastructure Inc. (Amec Foster Wheeler) for the planned mitigation
improvements located within the Villas at Savona complex located at 955 East Knox Road in
Chandler, Arizona. This report includes the results of the field exploration, laboratory testing and
an estimate of the vertical extents of soft soils beneath the building foundations.

2.0 PROJECT DESCRIPTION

Project specifics were provided by Carl Heerup, Heerup Engineering, PC (Heerup), via phone
calls and e-mails on November 19 & 20, 2015. The Villas at Savona is currently experiencing
settlement issues at various buildings within the complex namely Buildings 2, 3, 5, 6, 7, 11, 13,
and 15. It is understood that compaction grouting and foam injection grouting are being
considered for the mitigation of the settlement. Mr. Heerup has requested Amec Foster Wheeler
perform the field investigation for the proposed mitigation; including test borings and soil sample
collection, laboratory testing, and a geotechnical report in order to determine the depth of soft
soils below the existing building foundations. The field investigation included borings in close
proximity to Buildings 3, 6, and 13, and did not include the other buildings experiencing settlement
distress. An assessment of the mitigation suitability and development of the means and methods
of the settlement mitigation are not within the Amec Foster Wheeler scope of work. A site plan
provided by Heerup and edited by Amec Foster Wheeler is attached as Figure 1.

3.0 REVIEW OF EXISTING DATA

An existing Geotechnical Engineering Report for the Villlas at Savona, by TerraPacific
Consultants Inc. (TerraPacific) dated July 17, 2014, was provided by Heerup. The TerraPacific
exploration consisted of six borings throughout the complex. The test borings were advanced to
depths ranging from 28.5 to 30 feet using a CME 75 truck-mounted drill rig equipped with 8-inch
outside-diameter hollow-stem auger. Bulk, standard penetration tests (SPT) and open-end ring
samples were completed at selected intervals in the borings. The soil encountered was logged
by a TerraPacific field representative. Applicable portions of the TerraPacific report were
incorporated into the Amec Foster Wheeler report.

4.0 FIELD INVESTIGATION

4.1 Subsurface Exploration

On December 17, 2015, four exploratory borings were advanced at the project site adjacent to
Buildings 3, 6, and 13 to a depth of 20 feet below existing grade. Due to utility & access issues,
two of the proposed six locations were unable to be drilled. Access to the boring locations was
along the residential roadways and paths within the complex. The borings were located as close
to the buildings as possible to allow for drill rig and personnel access with the distance from the
buildings ranging from 10 to 15 feet. The test borings were completed using a CME 55 truck-
mounted drill rig equipped with 6 5/8-inch outside diameter hollow stem auger. The drill rig is
owned and operated by D&S Drilling, Inc.. Standard penetration testing (SPT) samples were
completed at selected intervals in the borings. During the field study, the soil encountered was

Heerup Engineering, PC
Chandler, Arizona December 30, 2015 Page 1