1028 BROADWAY 2016-01-01 MF Import

� � ExcAvnrioNs � lixc;n�alions :irc uot anlicip.ncd to hc grcalcr ticm �i fi�n dccp. I lo�vc��cr, c�c:rv�iiuns grcatrr ih;m �1 t��ci dcep can likcly bc tn�dc :i� icmpnr.iry opcn cw slo�ms depcnding on siic conslrainls. L•sr;rv;�tiuns mav also reyuired for underground utilities. 'Ihe stahiliq� of open cul slopes is a function uf soil t�pe. � grouqehv�ucr seepagc, siope inclination, slope height and nearby swfacc loads. 'Ihe usc of inadcyuatcly � Jcsigncd opcn cws could impact �hc sm6ili�y of ;i�jaccnt work arcas, exis�ing utiliiics, and cndangcr �,crsonncl. � fhe conu:�cto� perfomiing Ihc �vork h;�s the primaty responsibiliry fi�r proteclion of workmen aud :uljacent improvements. In our opinion, the contractor will be in the besl position io observc subsurfnce � cundilions continuously throughow the conslruction process and to respund to variable soil and groundwater conditiuns. 'I'herefore, the conuactor shnuld have ihe primary responsibiliry for deciding �vhether ur not to use open cut slopes fix much of'the excavations r,uher than some form of temporaq exc�vation suppurt, anJ for estnblishing thc safc inclination of ihe cut slope. Acceptable slopc � inclinatiuns for utilitics ;md nncillap� excavations should be detem�ined during construction. Because of the diversity o1'conslniction techniqucs and available shoring sy51Ci175,the design of temporary shoring is most apptopriately Ien up to the coniractor proposing to complete the installation. Temporary cut slopes � and shoring must comply with thc provisiuus ul"fi11e 2)6 1VAC, Part N, „Gscavation. Trcnching nnd Shoring." The excrvations will be completed primarily in (ill and medium stiff lo vciy s�iff silt and clay deposits. � 7'he following sections smnmarize the general exc.�vation recommendations. If candiiions allu�v, escavatinns fix d�e proposecl building tnay he accomplished using temponry cut slopcs. n Temporary Cut Slopes � � fbr planning puqioses.temporary unsupponed cW slopes more th�n 4 feet hieh may bc incli�wd :d 211:1 V nruiunm stuepness wilhin ihe silt and clay soils and no steeper Ihan 1.5H:IV in lhe dense gluciall} ( cm�solidaied soils. If signifirmi secpnge is present on the cut face or if f'nclures and shear zones arc encounia'ed in the silt and clay deposits then �he cW slopes may Lave to be flattcucd. Ilo�sever. tcmpur:uy cuts should be discussed with the geo�echnical engineer during linal design devclopment tu Ievalua�c suil:�ble cut slupe inclinations la the various portions of the excavaliun. 17ic above guidclines assume thsu surfacc loads such as traffic, cons�n�clion eyuipmen�, s�ockpiles or I141I(IIII�' Sll��)IICS\VIII I7C I�C�1 ;IWiI)� Gom ihc top o(thc cut slopcs a sufficicnt dis1i1I1CC SO II181 lI1C Sl:lVIIII)' � 01'lhe crcnvalion is not alTected. Wc recommcnd iha� Ihis dislance be at least 5 feet frotn thc top of tBe cut Ibr temporary cuts made at 1.51I:1 V or ilalter. � Temporary cut slopes shuuld be plunned such ihal thuy do not encroach on a II I:1 V inllucncc line projected down Gom thc alges of nearby or planued f'oundatirni clements. Watcr aitering excavations must bc collec�ed and routed away frotn prepared subgrade areas. 1✓c expect I that U�is may bc .scomplishcd by inst:dling a systcm of dninaga ditches and sumps aloug thc tuc of thc cut slopcs. Some slou�;hing anJ ravcling of the cut slopcs should be expccted. Temporary covering,such os henvy pinstic sheetiug��ith apprupriate b;dlast, shoutd be used to protect these slopes during periuds of I wcl \\'CHIIII'L S4'fT.:CL` H.IICi NIlO�� I'Oiil abocc cui slopzs shoul� bc picveutcd from ilowing ovcr ti�c slupe face by using b�•uns,draivage ditches,swales or other appropriue meihods. If tempor;uy cut sl��pes experiznee excessive sloughing or r�rveling during consWetion, it may become Inecessary to modify the cut sloucs to maintain safe wurking conditions. Slopes experiencing problems � F71rNo c,v3G-on7.nu___ Pngc9 Julr!7. ;OU.1' GEOENGINEER� � 5 �