摩擦滑(hua)(hua)(hua)移(yi)隔(ge)震(zhen)是開發(fa)應(ying)用(yong)較(jiao)早的(de)(de)(de)隔(ge)振技(ji)術之一(yi)(yi),所(suo)用(yong)的(de)(de)(de)摩擦材料(liao)多(duo)為(wei)沙石、石墨等廉(lian)價材料(liao),標記經(jing)濟且(qie)簡(jian)(jian)單易行(xing)。摩擦滑(hua)(hua)(hua)移(yi)隔(ge)震(zhen)系(xi)(xi)統(tong)(tong)通常有(you)隔(ge)離地(di)震(zhen)作用(yong)的(de)(de)(de)摩擦滑(hua)(hua)(hua)動(dong)(dong)機(ji)(ji)構(gou)和限位復位的(de)(de)(de)阻尼(ni)向(xiang)心(xin)機(ji)(ji)構(gou)組成,多(duo)為(wei)平面(mian)滑(hua)(hua)(hua)移(yi)隔(ge)震(zhen)系(xi)(xi)統(tong)(tong)。該(gai)系(xi)(xi)統(tong)(tong)不能自動(dong)(dong)復位,一(yi)(yi)般需要另外加設(she)復位裝(zhuang)置(zhi),且(qie)滑(hua)(hua)(hua)動(dong)(dong)性(xing)能離散性(xing)大、不易控制(zhi),滑(hua)(hua)(hua)移(yi)量過大可(ke)能導致(zhi)穿越隔(ge)震(zhen)層(ceng)的(de)(de)(de)非結(jie)構(gou)構(gou)件(jian)破壞,甚至可(ke)能發(fa)生(sheng)滑(hua)(hua)(hua)移(yi)失穩,這極(ji)大地(di)阻礙(ai)了滑(hua)(hua)(hua)移(yi)隔(ge)震(zhen)的(de)(de)(de)發(fa)展。為(wei)了解決平面(mian)滑(hua)(hua)(hua)移(yi)系(xi)(xi)統(tong)(tong)不能自動(dong)(dong)復位問題,Zayas等于1985年在美國加州大學伯克利分校研發(fa)了摩擦擺隔(ge)震(zhen)裝(zhuang)置(zhi),稱之為(wei)摩擦擺系(xi)(xi)統(tong)(tong)/支座(zuo)(Friction Pendilum System/Bearing,簡(jian)(jian)稱FPS/FPB)。該(gai)裝(zhuang)置(zhi)不僅具有(you)平面(mian)滑(hua)(hua)(hua)移(yi)隔(ge)震(zhen)裝(zhuang)置(zhi)的(de)(de)(de)對(dui)地(di)震(zhen)激勵頻率范圍(wei)的(de)(de)(de)低敏感性(xing)和高(gao)穩定性(xing),特有(you)的(de)(de)(de)圓弧滑(hua)(hua)(hua)動(dong)(dong)面(mian)還使其具有(you)復位功能,無需附設(she)阻尼(ni)向(xiang)心(xin)機(ji)(ji)構(gou),故而(er)在實際應(ying)用(yong)中更(geng)為(wei)簡(jian)(jian)便,且(qie)增加了隔(ge)震(zhen)裝(zhuang)置(zhi)的(de)(de)(de)可(ke)靠度。
摩擦(ca)擺隔(ge)震支(zhi)(zhi)(zhi)座(zuo)(zuo)(zuo)是將傳(chuan)統的平面(mian)(mian)滑(hua)(hua)移隔(ge)震裝置(zhi)的摩擦(ca)滑(hua)(hua)移面(mian)(mian)由平面(mian)(mian)改為(wei)球面(mian)(mian),從而(er)可(ke)依靠自(zi)(zi)(zi)身(shen)重力自(zi)(zi)(zi)動(dong)(dong)(dong)(dong)回復。該支(zhi)(zhi)(zhi)座(zuo)(zuo)(zuo)主要由上、下支(zhi)(zhi)(zhi)座(zuo)(zuo)(zuo)板和一(yi)個鉸接滑(hua)(hua)塊組(zu)成。摩擦(ca)擺隔(ge)震支(zhi)(zhi)(zhi)座(zuo)(zuo)(zuo)嵌在(zai)滑(hua)(hua)動(dong)(dong)(dong)(dong)容腔中的鉸接滑(hua)(hua)塊與滑(hua)(hua)動(dong)(dong)(dong)(dong)面(mian)(mian)具有相同的曲(qu)率半徑,可(ke)與滑(hua)(hua)動(dong)(dong)(dong)(dong)面(mian)(mian)完全貼合,并(bing)使上支(zhi)(zhi)(zhi)座(zuo)(zuo)(zuo)在(zai)支(zhi)(zhi)(zhi)座(zuo)(zuo)(zuo)滑(hua)(hua)動(dong)(dong)(dong)(dong)時(shi)始終保持水平。滑(hua)(hua)動(dong)(dong)(dong)(dong)面(mian)(mian)上涂有低(di)摩擦(ca)材料(liao),如聚四氟乙(yi)烯(xi)(特氟龍)等,可(ke)在(zai)滑(hua)(hua)動(dong)(dong)(dong)(dong)過程中耗(hao)散(san)能(neng)量。當(dang)滑(hua)(hua)動(dong)(dong)(dong)(dong)界(jie)面(mian)(mian)受(shou)到(dao)的地(di)震作用超過靜摩擦(ca)力時(shi),地(di)面(mian)(mian)水平運動(dong)(dong)(dong)(dong)會(hui)促使滑(hua)(hua)動(dong)(dong)(dong)(dong)在(zai)其圓弧面(mian)(mian)內滑(hua)(hua)動(dong)(dong)(dong)(dong),從而(er)迫使上部(bu)結構輕微抬高,發生單(dan)擺運動(dong)(dong)(dong)(dong)。然(ran)后(hou),支(zhi)(zhi)(zhi)座(zuo)(zuo)(zuo)會(hui)在(zai)自(zi)(zi)(zi)身(shen)受(shou)到(dao)的豎向荷(he)載作用下自(zi)(zi)(zi)動(dong)(dong)(dong)(dong)回復。
摩擦(ca)擺隔震(zhen)(zhen)支(zhi)座(zuo)的(de)(de)(de)水平(ping)力(li)為滑動面摩擦(ca)力(li)和上(shang)部結(jie)構(gou)沿滑道上(shang)升產生的(de)(de)(de)恢復力(li)的(de)(de)(de)合(he)力(li),而提供的(de)(de)(de)恢復力(li)使(shi)支(zhi)座(zuo)能(neng)依靠其承受的(de)(de)(de)重力(li)自(zi)動往中心(xin)位(wei)置回復,使(shi)地震(zhen)(zhen)響應得到控制(zhi),并且該(gai)支(zhi)座(zuo)的(de)(de)(de)剛度(du)中心(xin)有自(zi)動與(yu)隔震(zhen)(zhen)結(jie)構(gou)的(de)(de)(de)質(zhi)心(xin)重合(he)的(de)(de)(de)趨勢,因而能(neng)在更大 程度(du)上(shang)消除(chu)結(jie)構(gou)的(de)(de)(de)扭轉運(yun)動。摩擦(ca)擺隔震(zhen)(zhen)支(zhi)座(zuo)的(de)(de)(de)周期、豎(shu)向(xiang)承載力(li)、阻尼比、側重位(wei)移和抗(kang)拉(la)力(li)等指(zhi)標可以進行單獨控制(zhi),該(gai)特性十(shi)分便于設(she)計(ji)人員對隔震(zhen)(zhen)系(xi)統進行優化設(she)計(ji)。