2205 WALL ST RELIABLE SECURITY SERVICES 2018-01-01 MF Import

EVALUATION STATEMENTS FOR BUILDING TYPE 15: UNREINFORCED MASONRY BEARING WALL BUILDINGS These 6uildings indude strutn{ral efe�ne��ls that vary depending on the age of �he burfding and �o a lerser uten4 tht geographic location of the suucture. !�i 6itifdings buil� before 1900, �he majoriry ofJ7oar and roof consnuction cansisu of woad shea�hing supported by wood subframing. !n laige multistory buifdings, the J7oors orc cast-inpfact concrcte auppo.Ked 6y the unrcinjorced maronry walfs and/or steel or concrerc interiar fsaming. In 6uildings buift af(tr l950, unninforced masonry buildings with wood Jloors usualfy have plywood rother than board shtaU�ing. More rccencfy, in rcgions oj lawtr scismiciry, rhese buifdingr can includt J1oor and roojjraming (hal cunsistt of ineta( i•ck and concnte f+!! supponed by s�eel framing efemtnGt. The perimcter waUs, and possibly some intenrr wa!!s, an unrtinjorced masonry. 77it wa!ls may or may not 6e anchorcd to tht diaphragms. Ties 6enveen �he wa!!s and diaphmgmr ae more common for the 6earing wa!!s than for wafls rhaf are pamlfef ta du J/oor framing, Rooj des usually arc less common and mon eirarically spactd than Oiose at rhe Jloor levels. /nrenor pmfitions that inrerconnect rhe J7oon and roof can have the effect of reducing diaplvag»i displacements. Ac'dress the following evaluation statements, marlcing each either Uue (T) or false (F�. Statements that are found to be true ideutiFy issues that are acaptable according ro the criteria of this handbook; statements that are found to be falso identify iuues t6at need investigation. For guidauce in lhe investigation, ro[er [o the handboolc sec[ion indica[ed in pareuthesu at the end of the statement. Be advised that lhe numerical inditcs prcceded by an as[erisk (•) in these statements are based on high seismicity (A„ = 0.4). Adjusunents are reasonable for lower seismiciry. The appropriate adjustment is not necessarily a direu ratio o[ seismicity. BUILDING SYSTEhiS T � LOAD PATH: The structure contains a complete load path for seismic force effects from any horizontal direction that scrves to transfer the inertial forcu from the mass w the [oundation (NOTE: Write a brie( dcscription o( this linkage for each principal direction,) (Sec. 3.1) oT F REDUNDANCY: The structure will remain la[erally stable after the [ailure of an� single element. (Sec.3.2) QF WEAK STORY: Visual obscrvation or a Quick Check indicates Ihat there are no signiticant strength discontinuities in any ot the vertical elements in the lateral-force- resisling system; t6e story strength at any story is no[ less Ihan 80 percent o( the strengt6 of the story above. (Sec. 33.1) �f F SOFT STORY: Visual observation or a Quick Chock indiwtes that there are no signiticant stitfneu discontinuities in any of the vertical elements in tho la[eral-force- resisting system; the lateral stifFuess of a story is not less than 70 perceot of that in the story above or less than 80 percent o[ the averege stitCness of the three stories above. (Sec. 33.2) B•53 (Typc 15)