FEATURE ARTICLE Construction of foundation piles for the new Pacific Access Channel Expanding the Panama Canal – a Wider Path Between the Seas The expansion of the Panama Canal is one of the 25 biggest and boldest projects on the planet this decade, according to an article by Tim Newcomb in Popular Mechanics. At the cost of $5.25 billion, the project will create a new lane of traffic along the canal through the construction of an additional set of locks, doubling the waterways’ transport capacity. These new locks will enable the canal to handle larger ships. The Panama Canal serves more than 144 maritime routes connecting 160 countries. About 14,000 ships sail through the canal every year. Lock chambers raise and lower ships between different waterway levels. One lock system lifts ships from the Pacific up to the level of Gatun Lake, and another lock system lowers them at the Atlantic side. The water used to raise and lower the vessels in each set of locks comes from Gatun Lake by gravity through a system of culverts. The Panama Canal expansion project is comprised of four main tasks: constructing two new lock complexes, constructing a new Pacific Access Channel, dredging the waterways and raising the operational level of Gatun Lake. The new 6.1 km (3.8 mi) Pacific Access Channel will provide navigation access from the new Pacific locks to the existing Gaillard Cut, the narrowest stretch of the original Panama Canal. Two dams with a combined length of almost 4 km (2.5 mi) and a height of about 30 m (98.4 ft), referred to as Borinquen Dams 1E and 2E, form the new channel’s eastern bank. Two additional dams with a total length of 1.4 km (0.9 mi), known as the Borinquen Dams 1W and 2W, help form the western bank. Using Soilmec equipment, the Trevi Group branch in Panama (Trevi Ciment- aciones y Consolidationes SA, formerly Trevi Galante SA) conducted soil investi- gations and installed foundation piles, diaphragm walls and injection walls for a wide variety of functions and at various locations along the 80 km (49.7 mi) long Panama Canal that connects the Atlantic Ocean to the Pacific Ocean. Soil Investigation The canal is located within a sedimentary basin formed about 3 million years ago, when the Pacific Plate slid slowly under the Caribbean Plate. The entire area is characterized by a complex lithology, from fine grainy materials (sediments, sand and mud) to hard rock with resistance above 50 MPa (500 tsf). The Atlantic area is composed primarily of silt, clay, calcareous sandstone and volcanic tuff, whereas sedimentary and volcanic rocks dominate the Pacific sector. Soil investigations were performed to identify the subsurface conditions at select locations, drilling exploratory holes with varying depths and analyzing a total of 6,000 linear meters of soil: 3,500 m (11,500 ft) of soil on the Pacific side and 2,500 m (8,200 ft) on the Atlantic side. These soil tests included standard penetration tests (SPT) to determine the soil density, Lugeon tests to verify the permeability of the bedrock and Lefranc tests to measure the permeability of the soil. Soilmec SM-305, SM-5 and SM-8 multipurpose microdrilling rigs were used to drill and install the necessary instrumentation, including piezometers to monitor groundwater pressure and inclinometers to measure potential slope movement. AUTHORS Colombo Biserna, Trevi South America and Marco Chiarabelli, Soilmec North America DEEP FOUNDATIONS • MAR/APR 2016 • 79
