Case Study: Capella de Pedregal

General Contractor: Beck Group

Engineering: Ocean and Coastal Engineering, Dr. Max Shepard Crystal Engineering, Wayne Walker

Mexican resort chooses Polaris and Aquaterra for 100 year Hurricane wall

The new private resort named Capella de Pedregal in Cabo San Lucas was challenged with a design requirement of protecting the property from a 100 year storm event. The resort is built directly on the Pacific Ocean and is susceptible to catastrophic hurricanes and storms. The resort is very exclusive and boasts such luxuries as private infinite pools for the individual villa owners that overlook the Pacific Ocean. The resort was built directly on a mountain facing the Pacific Ocean so a tunnel had to be built through the mountain in order to bring all of the construction equipment and materials to the jobsite. The biggest challenge was to design a seawall that would withstand the 100 year storm.

The original design was to build a 6 Meter tall concrete seawall that would be partially buried in the sand for aesthetic purposes. The design called for sheetpiling to be placed in front of the footing for the massive concrete wall to act as additional scour protection. During the first phase of construction in 2007 the developer encountered 2 hurricanes and 1 tropical storm. This caused the water table to rise to a point that excavation for the footing of the wall was impossible. An emergency meeting was executed to formulate an alternative solution.

The General Contractor was faced with multiple obstacles because material had to be brought through a tunnel in the mountain. This made the traditional methods of using steel, concrete panels, and rock impossible to transport to the jobsite. Sheetpile was the only real solution to this problem but equipment to bring steel to the jobsite was impossible because of the cranes that would be needed. The use of synthetic sheetpile had never been used in heights exceeding 5 meters and so the engineers were faced with a big challenge.

The idea of constructing a wall using composite sheetpile was the most logical and cost effective solution since heavy equipment would not be needed and the material could be transported through the tunnel. The problem that faced the engineers is that synthetic sheetpile has deflection issues over 4 meters and wall failure could be catastrophic. The introduction of a new technology called Aquaterra became the only real solution.

Aquaterra is a system that combines the advantages of reinforced earth and sheetpile. For many years engineers have been trying to invent a way to connect Tensar Geogrid to sheetpile in order to eliminate deflection. The invention of Aquaterra suddenly became the answer that the engineers were looking for. By using a combination of sheetpile and Geogrid the engineers were able to design a wall that eliminated deflection on the sheetpile and offer a 100% synthetic solution that would meet the 100 year design criteria.

The next problem that the engineers faced was that the architects did not want the look of a sheetpile wall. In order to solve problem Crystal engineering developed a way to introduce a facia on the sheetpile made of shotcrete. This gave the architects the ability to put a stone, granite, or stucco facia on top of the sheetpile.