Hillside Slope Stabilization Utilizing Helical Anchors and Helical Piles in Southern California-PPT Presentation

PPT Presentation

Pdf Summary

The project stabilized a swimming pool and surrounding structures affected by settlement and lateral movement. Built in 2018 without deep foundations or retaining walls, the pool developed widening cracks in its shell and adjacent CMU walls, especially after rain. A geotechnical investigation found poorly compacted sandy soils, with compaction ranging from 82% to 85%.

Helfrich-Associates provided multidisciplinary engineering and consulting, using site mapping, test pits, hand augers, and existing foundation records to design a stabilization system. The work included 88 vertical helical piles and 27 helical tieback anchors supporting the pool, grade beams, spa, and perimeter walls. The pool shell cracks were repaired, and its coping was replaced and leveled.

The project also included a new 105-foot retaining wall, supported by piles and restrained by tiebacks spaced at eight-foot intervals. Settled sections of the pool deck were replaced with six-inch structural slabs supported on grade beams and helical piles. Drainage improvements, epoxy dowels, and tiebacks for fill slopes helped limit water penetration and lateral movement. Approximately 8,000 square feet of slope also received polyurethane soil densification.

Earth Contact Products supplied the helical piles and anchors. A four-person Dalinghaus installation crew completed the project in three phases over two months, coordinating with a concrete contractor. The completed project received the ECP Network’s 2019 Project of the Year Award and was featured in <em>Helical Pile World</em>.

Keywords

swimming pool stabilization

helical piles

helical tieback anchors

settlement damage

lateral movement

geotechnical investigation

retaining wall

soil densification

drainage improvements

concrete crack repair