目前，陜西瀝青路面鋪筑使用的找平基準主要有4種型式：一是固(gu)定(ding)基(ji)準，即(ji)懸線法；二是接觸(chu)跨越(yue)式浮動平衡(heng)梁基(ji)準；三是非接觸(chu)式電子(zi)平衡(heng)梁基(ji)準；四是滑靴(xue)式基(ji)準。實踐證明，在(zai)下(xia)(xia)面層(ceng)(ceng)、中(zhong)面層(ceng)(ceng)采(cai)用懸(xuan)線法，中(zhong)面層(ceng)(ceng)、上面層(ceng)(ceng)采(cai)用接(jie)觸跨越式浮動平(ping)衡(heng)梁基準或非接(jie)觸式電子平(ping)衡(heng)梁基準鋪筑的效果(guo)良好。4種方式可作以(yi)下(xia)(xia)比較(jiao)。

(1)使(shi)用(yong)固(gu)定(ding)基準(zhun)(zhun)（懸線法）能在(zai)(zai)較大范圍內(nei)準(zhun)(zhun)確地控制設(she)計標(biao)高、縱橫坡度、路面(mian)厚度和平整度。操(cao)作方(fang)法是：選用(yong)直徑2 mm的(de)高強鋼絲(si)，長度200 m，張緊(jin)度為(wei)800~1 000 N，基準(zhun)(zhun)線應(ying)盡量靠進熨平板(ban)，以減(jian)少厚度增量值。基準(zhun)(zhun)線兩(liang)根(gen)立桿(gan)的(de)間距一般為(wei)5~10 m，用(yong)兩(liang)臺精密水(shui)準(zhun)(zhun)儀(yi)監(jian)測立桿(gan)的(de)高程(cheng)，每兩(liang)根(gen)立桿(gan)之間鋼絲(si)繩的(de)撓度不大于2 mm，彎道(dao)處應(ying)加密。立桿(gan)要高于鋪層(ceng)75~150 mm，埋設(she)牢固(gu)，距鋪層(ceng)邊緣160~500 mm。鋼絲(si)架設(she)高程(cheng)應(ying)高于虛鋪高程(cheng)50~100 mm，用(yong)細(xi)鐵絲(si)綁(bang)緊(jin)在(zai)(zai)立桿(gan)支撐(cheng)架凹槽上。作業期間應(ying)有專(zhuan)人看管，嚴禁(jin)碰撞(zhuang)鋼絲(si)。

(2)使用(yong)(yong)接(jie)觸(chu)跨越式浮(fu)(fu)動(dong)(dong)平(ping)(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)梁(liang)(liang)(liang)(liang)(liang)(liang)時(shi)，為(wei)保證(zheng)面(mian)(mian)(mian)層(ceng)整(zheng)(zheng)體平(ping)(ping)(ping)(ping)整(zheng)(zheng)度(du)(du)，中面(mian)(mian)(mian)層(ceng)、上(shang)面(mian)(mian)(mian)層(ceng)用(yong)(yong)平(ping)(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)梁(liang)(liang)(liang)(liang)(liang)(liang)。為(wei)提高平(ping)(ping)(ping)(ping)整(zheng)(zheng)度(du)(du)，應盡量(liang)加長平(ping)(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)梁(liang)(liang)(liang)(liang)(liang)(liang)的長度(du)(du)，注(zhu)意滑(hua)靴和平(ping)(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)梁(liang)(liang)(liang)(liang)(liang)(liang)行(xing)走輪不要(yao)黏上(shang)瀝(li)青，以(yi)防(fang)影(ying)(ying)響(xiang)攤(tan)鋪(pu)(pu)(pu)(pu)層(ceng)的平(ping)(ping)(ping)(ping)整(zheng)(zheng)度(du)(du)。浮(fu)(fu)動(dong)(dong)平(ping)(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)梁(liang)(liang)(liang)(liang)(liang)(liang)有(you)很好的濾波作用(yong)(yong)，避免了固定基(ji)準折線和人為(wei)誤差的影(ying)(ying)響(xiang)，大(da)大(da)提高了路面(mian)(mian)(mian)平(ping)(ping)(ping)(ping)整(zheng)(zheng)度(du)(du)。跨度(du)(du)16~17.6 m的平(ping)(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)梁(liang)(liang)(liang)(liang)(liang)(liang)要(yao)求是(shi)(shi)直線攤(tan)鋪(pu)(pu)(pu)(pu)，攤(tan)鋪(pu)(pu)(pu)(pu)彎(wan)道(dao)時(shi)要(yao)求彎(wan)道(dao)的半徑(jing)大(da)于(yu)600 m，否則由(you)于(yu)彎(wan)道(dao)的變(bian)化引起(qi)平(ping)(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)梁(liang)(liang)(liang)(liang)(liang)(liang)滾輪和滑(hua)靴產(chan)生較大(da)的扭矩而(er)發(fa)生橫(heng)向(xiang)位移(yi)，不但(dan)起(qi)不到平(ping)(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)作用(yong)(yong)，反而(er)破壞整(zheng)(zheng)個平(ping)(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)系(xi)統(tong)(tong)，攤(tan)鋪(pu)(pu)(pu)(pu)出的路面(mian)(mian)(mian)厚(hou)薄不均勻(yun)，影(ying)(ying)響(xiang)路面(mian)(mian)(mian)的平(ping)(ping)(ping)(ping)整(zheng)(zheng)度(du)(du)。因(yin)此在(zai)(zai)(zai)攤(tan)鋪(pu)(pu)(pu)(pu)半徑(jing)小于(yu)600 m的彎(wan)道(dao)時(shi)，除(chu)攤(tan)鋪(pu)(pu)(pu)(pu)機轉向(xiang)應緩慢(man)過渡外(wai)，還應拆掉部分平(ping)(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)梁(liang)(liang)(liang)(liang)(liang)(liang)，使其平(ping)(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)梁(liang)(liang)(liang)(liang)(liang)(liang)變(bian)短，減(jian)小平(ping)(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)梁(liang)(liang)(liang)(liang)(liang)(liang)橫(heng)向(xiang)位移(yi)，提高路面(mian)(mian)(mian)的平(ping)(ping)(ping)(ping)整(zheng)(zheng)度(du)(du)。在(zai)(zai)(zai)用(yong)(yong)浮(fu)(fu)動(dong)(dong)平(ping)(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)梁(liang)(liang)(liang)(liang)(liang)(liang)鋪(pu)(pu)(pu)(pu)橫(heng)縫時(shi)，由(you)于(yu)此時(shi)平(ping)(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)梁(liang)(liang)(liang)(liang)(liang)(liang)的后半部分是(shi)(shi)在(zai)(zai)(zai)已(yi)經攤(tan)鋪(pu)(pu)(pu)(pu)壓實好的路面(mian)(mian)(mian)上(shang)，在(zai)(zai)(zai)攤(tan)鋪(pu)(pu)(pu)(pu)前(qian)應在(zai)(zai)(zai)平(ping)(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)梁(liang)(liang)(liang)(liang)(liang)(liang)滾輪下墊(dian)1塊長6 m、寬(kuan)20 cm、厚(hou)度(du)(du)與虛(xu)鋪(pu)(pu)(pu)(pu)系(xi)數相等(deng)的木板(ban)，攤(tan)鋪(pu)(pu)(pu)(pu)機起(qi)步時(shi)打開平(ping)(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)梁(liang)(liang)(liang)(liang)(liang)(liang)自動(dong)(dong)找(zhao)平(ping)(ping)(ping)(ping)系(xi)統(tong)(tong)開關。因(yin)為(wei)正(zheng)常使用(yong)(yong)平(ping)(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)梁(liang)(liang)(liang)(liang)(liang)(liang)時(shi)其后半部是(shi)(shi)在(zai)(zai)(zai)未壓實的虛(xu)鋪(pu)(pu)(pu)(pu)路面(mian)(mian)(mian)滾動(dong)(dong)，如(ru)果(guo)此時(shi)不墊(dian)木板(ban)，使用(yong)(yong)平(ping)(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)梁(liang)(liang)(liang)(liang)(liang)(liang)自動(dong)(dong)找(zhao)平(ping)(ping)(ping)(ping)系(xi)統(tong)(tong)會使鋪(pu)(pu)(pu)(pu)出的路面(mian)(mian)(mian)厚(hou)度(du)(du)減(jian)小。

(3)非接(jie)觸式(shi)(shi)電子平衡梁目前有激(ji)光式(shi)(shi)和(he)超(chao)(chao)(chao)聲波式(shi)(shi)。超(chao)(chao)(chao)聲波式(shi)(shi)平衡梁的超(chao)(chao)(chao)聲波探(tan)頭間距(ju)應(ying)不小于(yu)60 cm，探(tan)頭下緣距(ju)地面以80~100 cm為宜(yi)，超(chao)(chao)(chao)聲波探(tan)頭探(tan)測區域(yu)的半徑為30 cm，所(suo)以在探(tan)頭的正下方(fang)半徑30 cm范圍內應(ying)無雜物(wu)。所(suo)配備(bei)的可調控制(zhi)板，可根據實際(ji)情況(kuang)調節靈敏度(du)、增減鋪層厚(hou)(hou)度(du)和(he)液(ye)壓缸升(sheng)降反應(ying)速度(du)。攤鋪橫接(jie)縫時(shi)可在后面探(tan)頭下方(fang)設置厚(hou)(hou)度(du)等于(yu)松鋪系數的木板，以達到接(jie)縫良(liang)好(hao)的目的。