Pasadena Gold Line

The Los Angeles to Pasadena Gold Line Extension project consisted of a 13.7-mile extension of the Blue Line beginning at Union Station in Los Angeles and ending east of Sierra Madre Villa Avenue in Pasadena. This light rail transit (LRT) line consisted of a double tracked system using electric current overhead wire. The project was primarily at-grade following the abandoned Atchison Topeka & Santa Fe (ATSF) Railroad right-of-way. There were a total of 13 stations. The extension included an aerial structure in Chinatown, and depressed box sections in Highland Park and in the Old Town area of Pasadena. Near the southern portion of the alignment, a new yard and shop was also developed. The overall project was divided into ten (10) segments by the design-build Contractor.

Group Delta Consultants provided 10 segment reports, 13 station reports, two seismic retrofit reports, and one new pedestrian overcrossing report. Reports for Segments 4 and 8 included the Figueroa and Colorado boxes, which were constructed using cut-and-cover method. The reports provided recommendations for retaining walls, MSE walls, stations and platforms, track design, excavation and shoring, probabilistic seismic hazard assessment, static and seismic earth pressures for temporary shoring and permanent walls, racking displacement of the tunnel sections during seismic event, slope stability, Caltrans Structure Foundation reports, etc. This project was the first Design-Build commuter rail line in Los Angeles County.

Mission Valley East LRT (Green Line)

The Mission Valley East Light Rail Transit (Green Line) connects the Blue Line near Qualcomm Stadium in San Diego to the Orange Line near Grossmont Center in the City of La Mesa.  The overall project was divided into three segments: Grantville Segment (3.5 km), SDSU Segment (1.1 km), and La Mesa Segment (4.7 km)

Group Delta Consultants performed the geotechnical investigation and provided foundation design recommendations for seven bridge structures including the 1-mile long Grantville Viaduct and over 13,000 ft. of retaining walls

The Mission Valley East LRT project was awarded the 'Outstanding Civil Engineering Award' by the San Diego Section of the American Society of Civil Engineers (ASCE).

Mission Valley West LRT (Blue Line)

The Mission Valley West Extension of the San Diego “Trolley” extends along the San Diego River Valley, from San Diego’s “Old Town” area to Qualcomm Stadium. The 6+ mile project included nine bridges and /or elevated rail sections, four on-grade stations, and two major elevated stations.

Conditions along the alignment included saturated, unconsolidated, and liquefiable flood plain deposits to depths of up to 120 feet, potential settlement of unconsolidated river deposits, water table at or near the ground surface and undocumented fill areas with abundant oversize construction debris. Portions of the site are considered environmentally sensitive and site access requires coordination with appropriate regulatory agencies.

Group Delta Consultants provided geotechnical engineering services for 6+ miles of light rail trolley traversing unconsolidated sediments of San Diego River Valley. Services included field exploration, drilled shaft design, seismic criteria (the alignment crosses the Rose Canyon Fault), and various geotechnical studies addressing mitigating liquefaction to depths of more than 80 feet using stone columns, highly compressible soils and large settlement under embankment fills, potential scour at bridge sites.

Gold Line Eastside Extension

The Metro Gold Line Eastside Extension is a southeasterly extension of the Pasadena Gold Line from Union Station passing through the cities of Los Angeles and East Los Angeles, and is 5.8 miles long. The project consists of at-grade alignment, four existing bridges, and one 456-ft long new bridge across US 101, and a tunnel section (1.8 miles).

In addition to geotechnical evaluation for the at-grade section, Group Delta Consultants provided Preliminary Foundation Reports (PFRs) for the bridges, plus a Structure Foundation Report (SFR) and an Environmental Initial Site Assessment (ISA) for the bridge over US101. The 1,100-ft long, 9-span bridge over US101 is a cast-in-place pre-stressed concrete box girder with span lengths ranging from 85 to 155 ft. The geotechnical design was performed in accordance with Caltrans standards.

Alameda Corridor East

Group Delta Consultants provided geotechnical engineering services for the environmental impact report (EIR) for the Alameda Corridor East (ACE) railroad project. The ACE project included two railroad alignments extending form Los Angeles to Pomona through the San Gabriel Valley. Improvement along the two corridors included 25 grade separation and bridge projects in the Cities of Pomona (3), Los Angeles (1), Industry (12), San Gabriel (4), El Monte (2), Montebello (1), and the County of Los Angeles (2). Group Delta’s work included evaluation of geotechnical conditions, groundwater, earthquakes and seismicity, and flood hazards, at each of the 25 sites.