17264 Cheboygan Lock Down Steam Wall - Geotechnical Investigation - 2004.pdf

This document is a geotechnical investigation report prepared by Soils & Structures Inc. for the Cheboygan Lock Evaluation project located in Cheboygan, Michigan. The investigation was conducted on August 23, 2004, and involved three test borings drilled to depths of 40.0 and 41.0 feet in accordance with ASTM D 1586 procedures. The purpose of the investigation was to provide soil-related information for evaluating an existing lock structure, which is a concrete structure with a depth of 23.35 feet and a length of approximately 100 feet.

The soil investigation revealed a general profile consisting of fill to a depth of up to 25.0 feet over clay layers, with varying soil conditions. The soil layers include a reddish-brown low plasticity clay (fill and upper clay), a brown fine to coarse sand layer, and a lower gray sandy clay with traces of gravel and cobbles. Groundwater was observed at depths of 27.5 to 32.5 feet, with water levels varying between 577.5 and 593.5 feet. The report includes a summary of soil properties, noting that the liquefaction potential of the soil underlying the lock is low, with the sand and lower clay layers having sufficient density and strength to resist liquefaction during a moderate earthquake.