1011 39TH ST 2016-01-01 MF Import

GEOTECHNICAI. ENGINEERING STUD� Susan and Thomas Zakos E-10138 August 20, 2002 Page 6 Pin Pile Retaining Wall In our opinion, the existing railroad ii� retaining wall can be replaced with a structural retaining wall consisting of steel pin piles and wood lagging. These wails are well suited to areas where access is limited and where large scale excavation and earthworlc is not feasible. "fypically four-inch diameter steel pipes spaced foiu feet on center are driven along the alignment of the proposed wall. Lagging consistinc� o` 4" X 12" pressure treated wood is then placed between the steel pipes to support the backtill soils. The piles are typically restrained from movement by anchors that are coiznected to the fsce of the wa�l. Based on the conditi�ns observed at the site, it is our opinion the existing railroad tie wall can be removed and then replaced with a structural pin pde wali located along the same alignment. ECI can provide more information on tliis type of wall system, and the names of contractors, if requested. A scheniatic detail of a pin pile wall is depicted on the attached Plate 4. In our opinion, the steel pipe piles used to construct the wall can also be used to re-support the deck posts that have exhibited lateral movement. The steel pipe piles used to construct the new wall typically consist of four-inch diameter Schedule 40 steel pipe. Typically the required embedment of the steel pipe piles below the bottom of tlie wall will be in tlie range of 1 .5 to 2.0 times t��e lieiglit of the wall. Assuming a wall height o( eic�l�t feet, the total lenc�th of the steel pipe piles will likely be in the ranfle of twenty (20) to twenty-five (25) feet. For preliminary design cf the retaining wall, the following gectechnical design parameters can be considered: Active Earth Pressure U=rec- Draining Soil Backfill) 35 pcf Active EartL Pressure (Lightweight Foam Fill) 15 pcf Passive Pressure (Pin Piles) 300 pcf (two pile diameters) Footing Surcharc�e (Where Applicable) 100 ps( (rectangular distJ A structural engineer will need to des:gn the wall. ECI can provide names of structural engineers familiar with designing this type of vdall system. ECI should observe the installation of the pin piles and wall anchors on a f�ll-time basis. ECI si,ni�ld also observe load testing of the tieback anchors that will likely be �e�essary to restrain the wall. Ee�th Cunsietanls, Im:. _—� --'—___ . _ . . . ._ >, .�ah+.�P �..is �_ . . . ._.._r--- ��-..-.�w�.-rn,—�.��. �._. ♦.,:. ..._ .. :.. ._t��'r::a:_.+r.4Y=n:K�&'ie'�']�y.LlAi3_....�.;-_ _' ?u,.�ra-:m.r .. Slin��+ „'i ...Yf. �