摩擦(ca)(ca)滑(hua)(hua)(hua)移(yi)隔(ge)(ge)(ge)震(zhen)(zhen)(zhen)是(shi)開發(fa)應用較早的隔(ge)(ge)(ge)振(zhen)技術之(zhi)一(yi),所用的摩擦(ca)(ca)材料多為沙石、石墨等(deng)廉(lian)價(jia)材料,標記經濟且簡單易(yi)行。摩擦(ca)(ca)滑(hua)(hua)(hua)移(yi)隔(ge)(ge)(ge)震(zhen)(zhen)(zhen)系統(tong)(tong)通常有(you)隔(ge)(ge)(ge)離(li)地震(zhen)(zhen)(zhen)作用的摩擦(ca)(ca)滑(hua)(hua)(hua)動(dong)(dong)機(ji)構(gou)和(he)限位(wei)復(fu)(fu)位(wei)的阻(zu)尼向心機(ji)構(gou)組成,多為平(ping)面滑(hua)(hua)(hua)移(yi)隔(ge)(ge)(ge)震(zhen)(zhen)(zhen)系統(tong)(tong)。該系統(tong)(tong)不(bu)(bu)能(neng)自(zi)動(dong)(dong)復(fu)(fu)位(wei),一(yi)般需要另(ling)外加設復(fu)(fu)位(wei)裝置(zhi),且滑(hua)(hua)(hua)動(dong)(dong)性能(neng)離(li)散性大、不(bu)(bu)易(yi)控(kong)制,滑(hua)(hua)(hua)移(yi)量過大可能(neng)導致穿越隔(ge)(ge)(ge)震(zhen)(zhen)(zhen)層的非(fei)結構(gou)構(gou)件(jian)破壞,甚至可能(neng)發(fa)生滑(hua)(hua)(hua)移(yi)失穩,這(zhe)極大地阻(zu)礙了(le)滑(hua)(hua)(hua)移(yi)隔(ge)(ge)(ge)震(zhen)(zhen)(zhen)的發(fa)展。為了(le)解決平(ping)面滑(hua)(hua)(hua)移(yi)系統(tong)(tong)不(bu)(bu)能(neng)自(zi)動(dong)(dong)復(fu)(fu)位(wei)問(wen)題,Zayas等(deng)于1985年在美國加州大學伯克利分(fen)校研發(fa)了(le)摩擦(ca)(ca)擺隔(ge)(ge)(ge)震(zhen)(zhen)(zhen)裝置(zhi),稱(cheng)之(zhi)為摩擦(ca)(ca)擺系統(tong)(tong)/支座(Friction Pendilum System/Bearing,簡稱(cheng)FPS/FPB)。該裝置(zhi)不(bu)(bu)僅具有(you)平(ping)面滑(hua)(hua)(hua)移(yi)隔(ge)(ge)(ge)震(zhen)(zhen)(zhen)裝置(zhi)的對(dui)地震(zhen)(zhen)(zhen)激(ji)勵頻率范圍(wei)的低敏感性和(he)高穩定性,特有(you)的圓弧滑(hua)(hua)(hua)動(dong)(dong)面還使其具有(you)復(fu)(fu)位(wei)功能(neng),無需附設阻(zu)尼向心機(ji)構(gou),故而在實際應用中更為簡便,且增加了(le)隔(ge)(ge)(ge)震(zhen)(zhen)(zhen)裝置(zhi)的可靠(kao)度。
摩擦擺隔(ge)震(zhen)支(zhi)座(zuo)(zuo)是將傳統的(de)(de)平(ping)面(mian)滑(hua)(hua)移隔(ge)震(zhen)裝置的(de)(de)摩擦滑(hua)(hua)移面(mian)由(you)平(ping)面(mian)改為球(qiu)面(mian),從而(er)(er)可依靠自(zi)身(shen)重(zhong)力自(zi)動(dong)(dong)(dong)(dong)(dong)(dong)回復(fu)。該支(zhi)座(zuo)(zuo)主要由(you)上(shang)、下支(zhi)座(zuo)(zuo)板和一(yi)個鉸(jiao)接(jie)滑(hua)(hua)塊組成。摩擦擺隔(ge)震(zhen)支(zhi)座(zuo)(zuo)嵌在(zai)(zai)滑(hua)(hua)動(dong)(dong)(dong)(dong)(dong)(dong)容(rong)腔中的(de)(de)鉸(jiao)接(jie)滑(hua)(hua)塊與滑(hua)(hua)動(dong)(dong)(dong)(dong)(dong)(dong)面(mian)具有相同的(de)(de)曲率(lv)半徑(jing),可與滑(hua)(hua)動(dong)(dong)(dong)(dong)(dong)(dong)面(mian)完全(quan)貼合,并使上(shang)支(zhi)座(zuo)(zuo)在(zai)(zai)支(zhi)座(zuo)(zuo)滑(hua)(hua)動(dong)(dong)(dong)(dong)(dong)(dong)時(shi)始終保持水平(ping)。滑(hua)(hua)動(dong)(dong)(dong)(dong)(dong)(dong)面(mian)上(shang)涂(tu)有低摩擦材(cai)料,如聚四氟(fu)乙烯(特氟(fu)龍)等,可在(zai)(zai)滑(hua)(hua)動(dong)(dong)(dong)(dong)(dong)(dong)過(guo)程中耗散能量。當滑(hua)(hua)動(dong)(dong)(dong)(dong)(dong)(dong)界(jie)面(mian)受到的(de)(de)地(di)震(zhen)作用超過(guo)靜摩擦力時(shi),地(di)面(mian)水平(ping)運(yun)(yun)動(dong)(dong)(dong)(dong)(dong)(dong)會促使滑(hua)(hua)動(dong)(dong)(dong)(dong)(dong)(dong)在(zai)(zai)其(qi)圓弧面(mian)內滑(hua)(hua)動(dong)(dong)(dong)(dong)(dong)(dong),從而(er)(er)迫使上(shang)部結(jie)構輕微(wei)抬(tai)高,發(fa)生單(dan)擺運(yun)(yun)動(dong)(dong)(dong)(dong)(dong)(dong)。然(ran)后(hou),支(zhi)座(zuo)(zuo)會在(zai)(zai)自(zi)身(shen)受到的(de)(de)豎向(xiang)荷載作用下自(zi)動(dong)(dong)(dong)(dong)(dong)(dong)回復(fu)。
摩(mo)擦(ca)擺隔震支座的(de)(de)(de)水(shui)平力(li)為滑動(dong)面摩(mo)擦(ca)力(li)和(he)上部結構沿(yan)滑道上升(sheng)產生的(de)(de)(de)恢(hui)復(fu)力(li)的(de)(de)(de)合(he)力(li),而提供的(de)(de)(de)恢(hui)復(fu)力(li)使支座能依靠其承受(shou)的(de)(de)(de)重(zhong)力(li)自(zi)動(dong)往中心(xin)位置(zhi)回復(fu),使地震響應得到控制,并且該支座的(de)(de)(de)剛度(du)中心(xin)有自(zi)動(dong)與隔震結構的(de)(de)(de)質心(xin)重(zhong)合(he)的(de)(de)(de)趨勢,因而能在更大 程度(du)上消除結構的(de)(de)(de)扭(niu)轉運動(dong)。摩(mo)擦(ca)擺隔震支座的(de)(de)(de)周(zhou)期、豎向承載力(li)、阻(zu)尼比、側重(zhong)位移和(he)抗拉力(li)等指標可(ke)以進(jin)行(xing)單獨(du)控制,該特性十(shi)分(fen)便于(yu)設(she)計人員對隔震系統(tong)進(jin)行(xing)優化設(she)計。