Engineering Disciplines


Services

Breakwaters, Jetties, & Groins

Pillar Point Harbor, Half Moon Bay, CA.

A breakwater system was designed for development of an extensive recreational and commercial fishing boat berthing facility located within a semi-protected Federal harbor of refuge on the open coast. Alternative methods were studied to provide shelter from deep water storm swell transmitted through existing and permeable rubble-mound structures, and short period seas locally generated within a broad inner harbor fetch. A matrix of breakwater cross-sections and layouts was formulated and analyzed to select an optimum plan that achieved the desired level of wave attenuation; minimized adverse wave reflection at the specially configured entrance; satisfied navigation maneuvering and visibility requirements; and maintained acceptable water circulation via natural tidal flushing processes. Physical hydraulic model tests were conducted in a small-scale ripple tank to economically assess the merits of the 49 alternative plans that were considered. The preferred plan consisted of over 3,300 feet of rubble-mound breakwater, including a 1,200-foot detached offshore segment. NCI provided the various oceanographical wave and current studies to specify the project's design criteria; prepared the detailed structural design of the preferred plan; evaluated and approved potential quarry stone sources for the multi-layered cross-section; and provided construction inspection and consultation services.

Sunroad Marina and Breakwater, San Diego, CA.

Premised upon an oceanographic study of the Sunroad Marina site on East Harbor Island in the San Diego Bay, Noble Consultants planned and engineered a sheet pile breakwater of prestressed concrete to achieve necessary wave attenuation for the berthing facilities along the marina's eastern boundary. Noble also designed and prepared engineering drawings and specifications for the complete 550-boat marina, including docks, pilings, gangways, electrical and mechanical facilities and appurtenances.

top

Groin No. 1 Modifications, Ventura, CA.

Preliminary engineering and design studies were performed by NCI to improve the existing Federal structure. A 100-foot rubble-mound spur was designed using hydraulic model test parameters to remedy localized beach erosion. The design included void sealing of the groin's core to reduce upcoast sand leakage, and rebuilding of a portion of the groin's mid-section to repair structural deficiencies. NCI prepared the detailed design plans and construction documents, supported the permit application process, and furnished on-site construction consultation.

Las Tunas GHAD Groin Field Demolition/Replacement, Malibu, CA.

NCI prepared the plans and specifications for removing an existing deteriorating groin field consisting of eight sheet pile groins. NCI services also included consultation during contractor bidding and daily onsite construction inspection during groin removal. Subsequently, a beach monitoring program was conducted to observe and measure sand levels over the following two years. In addition, NCI was involved in the planning process for replacement of the removed groin field with a new groin field.

Oceanside Beach Stabilization, Oceanside, CA.

NCI performed the preliminary engineering design and prepared a beach stabilization plan for 14,000 lineal feet of Oceanside Beach (between Oceanside Pier and Buena Vista Lagoon). The plan consisted of four alternative groin field layouts, initial sand nourishment to fill the groin field cells, and annual maintenance sand nourishment. Cost estimates for the four alternative plans were also developed. The four groin field layouts consisted of eight to thirteen low profile, wave-absorbent groins that would be adjustable in height and length to extend offshore to the -10 feet MSL bottom contour. Their average length would be between 500 to 650 feet, with average groin spacing of approximately 1,000 feet. However, the southerly two groins would act as transitional groins, and therefore be progressively smaller in length and closer in spacing to allow for adequate bypass of sand to their south. In addition to the approximately one million cubic yards of initial sand nourishment, it was recommended that the Corps of Engineers' harbor entrance sand bypass line be extended beyond the southerly most downcoast groin. This plan was recommended after evaluating the oceanographical, sediment transport and shoreline erosional conditions occurring along Oceanside's beach and along the entire Oceanside littoral cell, in addition to reviewing the Corps of Engineers' proposed groin field and consulting with their technical staff.

top

Emeryville Breakwater Replacement, Emeryville, CA.  

Work involved the bathymetric survey, site reconnaissance, coastal engineering analysis, engineering design, opinion of construction cost, and the preparation of construction drawings and specifications for the replacement of the deteriorated timber breakwater with a concrete structure.  The design consisted of precast concrete panels and batter piles and a cast-in-place concrete deck and cap.  Half of the structure provides fishing and public access.  Special details were included in the design to enhance water circulation and encourage native oyster colonization.  A design challenge consisted of specifying sheet pile and batter pile lengths for the highly variable foundation soil profile.

The work also included design for replacement of a windsurfing launch ramp.  NCI performed construction engineering and resident inspection during the construction.

top

© Noble Consultants, Inc.