2701 ROCKEFELLER AVE NIMBUS 2024-01-03

Opporansh Zone Development LLC June 6, 2010 JN 19152 Page a If easements from neighboring property owners to install tieback anchors (or soil nails) cannot be obtained, it may be necessary to utilize internal braces (rakers) to restrain the soldier piles. Soldier piles restrained by rakers can undergo more deflection than do tied -back or cantilever piles, due to the temporary sloped excavation that is necessary in front of the soldier piles to install the rakers and thrust blocks. This requires that the shoring designer closely evaluate the temporary conditions that exist before raker installation. We should be contacted early in the design process if rakers are necessary, In order to provide the appropriate design considerations. It is Important that the shoring design provides sufficient working room to drill and install the soldier piles, without needing to make unsafe, excessively steep temporary cuts. Out slopes should be planned to Intersect the backside of the drilled holes, not the back of the lagging. Lateral movement of the soldier piles below the excavation level will be resisted by an ultimate passive soil pressure equal to that pressure exerted by a fluid with a density of 600 pcf. This soll pressure is valid only for a level excavation In front of the soldier pile; it ads on two times the grouted pile diameter. Cut slopes made in front of shoring walls significantly decrease the passive resistance. This includes temporary cuts necessary to Install Infernal braces or rakers. The minimum embedment below the floor of the excavation for cantilever soldler piles should be equal to the height of the "stick-up." Tied -back soldier piles should be embedded no less than 10 feet below the lowest point of the excavation, including footing and utility excavations. The vertical capacity of soldier piles to carry the downward component of the tieback forces will be developed by frictional shaft resistance along the embedded pile length. Pile Shaft Friction 2,000 psf Pile End -Bearing 20,000 psf Where: psf Is Pounds per Square Foot. The above values assume that the excavation is level in front of the soldier pile and that the bottom of the pile Is embedded a minimum of 10 feet below the floor of the excavation. For the pile and -bearing to be appropriate, the bottom of the drilled holes must be cleaned of loosened soil. The shoring contractor should be made aware of this, as it may affect their Installation procedures. The concrete surrounding the embedded portion of the pile must have sufficient bond and strength to transfer the vertical load from the steel section through the Concrete into the soil. 7feheekgnchom General considerations for the design of fied-back anchors or braced soldier-plle walls where two or more anchors or braces are used are presented on Plate 7. We recommend Installing tieback anchors at Inclinations between 20 and 30 degrees below horizontal. The tieback will derive its capacity from the soil -grout strength OEOTEdf CONSULTRNrS, INC.