摩(mo)擦(ca)滑(hua)(hua)移隔震(zhen)(zhen)(zhen)是開(kai)發(fa)(fa)應(ying)用(yong)(yong)較早的(de)(de)(de)(de)隔振技術之一,所(suo)用(yong)(yong)的(de)(de)(de)(de)摩(mo)擦(ca)材料(liao)多為(wei)沙石(shi)、石(shi)墨等廉(lian)價材料(liao),標記經濟且(qie)(qie)簡單易(yi)行(xing)。摩(mo)擦(ca)滑(hua)(hua)移隔震(zhen)(zhen)(zhen)系(xi)統(tong)(tong)通常有隔離地(di)震(zhen)(zhen)(zhen)作用(yong)(yong)的(de)(de)(de)(de)摩(mo)擦(ca)滑(hua)(hua)動(dong)機構和(he)(he)限位復位的(de)(de)(de)(de)阻尼(ni)向心(xin)機構組成(cheng),多為(wei)平(ping)面(mian)滑(hua)(hua)移隔震(zhen)(zhen)(zhen)系(xi)統(tong)(tong)。該系(xi)統(tong)(tong)不能自(zi)動(dong)復位,一般需要(yao)另外加設(she)復位裝置,且(qie)(qie)滑(hua)(hua)動(dong)性(xing)(xing)(xing)能離散性(xing)(xing)(xing)大(da)、不易(yi)控制(zhi),滑(hua)(hua)移量過(guo)大(da)可(ke)(ke)能導致穿越隔震(zhen)(zhen)(zhen)層的(de)(de)(de)(de)非結構構件破壞(huai),甚至可(ke)(ke)能發(fa)(fa)生滑(hua)(hua)移失穩,這極大(da)地(di)阻礙了(le)(le)滑(hua)(hua)移隔震(zhen)(zhen)(zhen)的(de)(de)(de)(de)發(fa)(fa)展。為(wei)了(le)(le)解決平(ping)面(mian)滑(hua)(hua)移系(xi)統(tong)(tong)不能自(zi)動(dong)復位問題,Zayas等于1985年(nian)在美國加州大(da)學伯克利分校研發(fa)(fa)了(le)(le)摩(mo)擦(ca)擺隔震(zhen)(zhen)(zhen)裝置,稱(cheng)之為(wei)摩(mo)擦(ca)擺系(xi)統(tong)(tong)/支座(Friction Pendilum System/Bearing,簡稱(cheng)FPS/FPB)。該裝置不僅具有平(ping)面(mian)滑(hua)(hua)移隔震(zhen)(zhen)(zhen)裝置的(de)(de)(de)(de)對(dui)地(di)震(zhen)(zhen)(zhen)激勵頻率范圍(wei)的(de)(de)(de)(de)低敏感性(xing)(xing)(xing)和(he)(he)高穩定性(xing)(xing)(xing),特有的(de)(de)(de)(de)圓(yuan)弧(hu)滑(hua)(hua)動(dong)面(mian)還使其(qi)具有復位功能,無需附設(she)阻尼(ni)向心(xin)機構,故而在實際應(ying)用(yong)(yong)中(zhong)更(geng)為(wei)簡便,且(qie)(qie)增加了(le)(le)隔震(zhen)(zhen)(zhen)裝置的(de)(de)(de)(de)可(ke)(ke)靠(kao)度。
摩(mo)擦擺隔(ge)震(zhen)(zhen)支(zhi)座(zuo)(zuo)是將傳統的(de)平面(mian)(mian)滑(hua)移隔(ge)震(zhen)(zhen)裝置(zhi)的(de)摩(mo)擦滑(hua)移面(mian)(mian)由平面(mian)(mian)改為球面(mian)(mian),從而(er)可依靠自身重(zhong)力自動(dong)(dong)回(hui)復。該支(zhi)座(zuo)(zuo)主要由上、下(xia)支(zhi)座(zuo)(zuo)板和(he)一(yi)個(ge)鉸接(jie)滑(hua)塊組(zu)成。摩(mo)擦擺隔(ge)震(zhen)(zhen)支(zhi)座(zuo)(zuo)嵌(qian)在(zai)滑(hua)動(dong)(dong)容腔中(zhong)的(de)鉸接(jie)滑(hua)塊與(yu)滑(hua)動(dong)(dong)面(mian)(mian)具有(you)相同的(de)曲(qu)率(lv)半徑,可與(yu)滑(hua)動(dong)(dong)面(mian)(mian)完全貼(tie)合,并(bing)使上支(zhi)座(zuo)(zuo)在(zai)支(zhi)座(zuo)(zuo)滑(hua)動(dong)(dong)時始(shi)終保持(chi)水平。滑(hua)動(dong)(dong)面(mian)(mian)上涂有(you)低摩(mo)擦材料(liao),如聚四(si)氟乙烯(特氟龍)等,可在(zai)滑(hua)動(dong)(dong)過程(cheng)中(zhong)耗(hao)散能量。當(dang)滑(hua)動(dong)(dong)界面(mian)(mian)受到的(de)地(di)震(zhen)(zhen)作用超過靜摩(mo)擦力時,地(di)面(mian)(mian)水平運動(dong)(dong)會(hui)促使滑(hua)動(dong)(dong)在(zai)其圓弧面(mian)(mian)內(nei)滑(hua)動(dong)(dong),從而(er)迫使上部結構輕微(wei)抬高,發生單擺運動(dong)(dong)。然(ran)后,支(zhi)座(zuo)(zuo)會(hui)在(zai)自身受到的(de)豎(shu)向荷(he)載作用下(xia)自動(dong)(dong)回(hui)復。
摩擦(ca)擺隔震支座(zuo)(zuo)的水平力(li)(li)(li)為滑動(dong)(dong)面摩擦(ca)力(li)(li)(li)和上(shang)部結構沿滑道上(shang)升產生的恢復力(li)(li)(li)的合力(li)(li)(li),而提(ti)供(gong)的恢復力(li)(li)(li)使支座(zuo)(zuo)能依靠其承受(shou)的重力(li)(li)(li)自動(dong)(dong)往中心(xin)位置回復,使地震響應得到控制(zhi),并(bing)且該支座(zuo)(zuo)的剛度中心(xin)有自動(dong)(dong)與隔震結構的質(zhi)心(xin)重合的趨勢,因而能在更大 程(cheng)度上(shang)消除結構的扭轉(zhuan)運動(dong)(dong)。摩擦(ca)擺隔震支座(zuo)(zuo)的周期、豎向承載力(li)(li)(li)、阻(zu)尼比(bi)、側重位移和抗拉力(li)(li)(li)等指標可以進(jin)行(xing)單獨控制(zhi),該特性十分便(bian)于設計人員對(dui)隔震系(xi)統進(jin)行(xing)優化設計。