Efrain Quinonez
Efrain is one of Drill Tech’s Senior Tunnel Superintendents, providing on-site supervision to ensure the safety and quality of the project. He has over 30 years of tunneling expertise that ranges from major rapid transit projects to hand excavated tunnels and shafts. Mr. Quinonez’s experience includes sequential excavation and support methods (SEM/NATM) tunneling, hand mining, and TBM excavation tunnels. His specialization is in trenchless tunneling such as boring and jacking.
Efrain's Featured Projects
CADOT I-80 Weimer Culvert Replacement | Weimer, CA
Superintendent
Drill Tech installed a 250' long 72" diameter steel pipe over an existing 48" CMP installed during the construction of I-80 coming down the grade from Colfax, CA. The existing pipe was showing signs of degradation, rusting, and was on the verge of collapsing in many locations. Drill Tech used pipe hammering methods to hammer/push the new pipe through the ground under the freeway and swallow the existing pipe, requiring the utilization of a 34" diameter pneumatic hammer in conjunction with a hydraulic pipe ramming sled. All work was performed about 55' below highway grade without impacting the traveling public on the highway to complete the culvert replacement. The project also included soil nail retaining walls, jacking sled installation with backstop, and thrust resistance piles and creek water diversion work.
CADOT SR 1 Culvert Replacement | Fort Ross, CA
Superintendent
The California Department of Transportation contracted Drill Tech to perform a culvert replacement off the coast of California under Highway 1. Drill Tech rammed a 90', 108" diameter steel pipe with 1.25" wall thickness under the road using a large pneumatic Hammerhead rammer weighing 27,000 pounds. This advanced the new pipe over the old, corrugated pipe which was cut up and removed. A pumped stream diversion and full-time traffic control were established to set up ramming equipment. 2,000 SF of temporary shoring, 300 CY of excavation and 85 CY of structural concrete were completed to construct a concrete headwall, and the placement of 1,200 tons of riprap erosion protection finished the job.
San Vicente Bypass Pipeline | Lakeside, CA
Superintendent
Drill Tech was the tunnel constructor of this project and operated as the Engineer of Record for the ground support systems. We performed 930' of drill/blast and roadheader mix excavation of an 8' diameter horseshoe shape tunnel that was followed by the installation of a 48" diameter reinforced concrete pipe and annular cellular grout. Ground support consisted of rock bolts, shotcrete in the granitic rock, and steel sets in the conglomerate. Drill Tech performed 850 SF of Soil Nail Portal Shoring.
