Retaining Wall Design
Paul is one of the leading authorities on retaining wall design. His careful observations and innovations have led to the ubiquitous tied-back anchored system we know today.
Tied-back anchorage of excavations was in its infancy in 1968 when Paul began measuring and recording the performance of excavation support. At Park Place in Seattle, Washington, Paul showed the reliable concrete-to-Seattle-clay friction to be 1,000 psf. This led to the first tied-back shoring system in the Seattle area where the anchorage used the clay for resistance.
As geotechnical engineer of record for this 44-story Bank of California tower, Paul further advanced the shoring technology when a 65-foot deep cut was made in Seattle clay. Such a cut had not been previous attempted due to the difficult properties of the clay. Working with the late Professor James Duncan of Berkeley and Dr. Wayne Clough (now Secretary of the Smithsonian), Paul developed the nonlinear stress-dependent properties of the over-consolidated clay. He then applied the factors in a finite element analysis of the excavation support system. The results were slightly better than predicted with excavation movements on the order of one inch.
Paul has gone on to design over 300 earth retention systems all over the United States and in other countries. He designed the first tied-back systems ever in Portland, Atlanta, Dallas, Denver, Salt Lake City, and Quito, Ecuador.
1969 Bank of California Building Basement Shoring, Seattle, Washington
This extensive job involved excavation support design for a forty-story building in downtown Seattle using tied-back soldier piles for the 65-foot-deep full block basement shoring. It required extensive use of FEM (finite element method) analysis of the excavation/anchor tensioning sequence. Instrumentation results agreed well with the elaborate geo-instrumentation used during construction.
2016 Akamai Gardens Subdivision, Kailua, Oahu
Akamai Gardens is an eight-plot subdivision on the edge of Enchanted Lake in Kailua. Soft soil deposit in the lake makes deep foundations necessary, even for houses. Meta Engineering designed and supervised the construction of extensive DuraBloc walls at the back of the lots on the edge of the lake. Even though the blocs were supported on micropiles, there was still erosion and shifting in recent years.
In 2024, the crew returned to control erosion and install mini piers under the blocs.
Meta Engineering 