四、跑道基礎施工規范:
1. 地基
(1) 一般較好的土,可直接壓實(shi)或夯實(shi)即可;
(2) 下沉性大(da)(da)的(de)和(he)含水量(liang)大(da)(da),松軟呈橡皮狀的(de)土,必須(xu)更換和(he)加(jia)固(gu),腐植土不能做為(wei)基(ji)土,應(ying)進行更換;
(3) 在結冰(bing)地區,地基表面應在冰(bing)結線以下,以防凍膠(jiao)破壞朔膠(jiao)面層;
(4) 基土過(guo)干或過(guo)濕應適當加水或曬(shai)干,以達到壓(ya)實最佳含水率為宜(yi);
(5) 用碎卵(luan)石(shi)或磚(zhuan)等作基土表(biao)面(mian)處(chu)理時,宜采用粒徑(jing)為40-60MM的塊(kuai)料,壓入深度(du)不應小(xiao)于40MM;
(6) 基土(tu)如需要更換時,應(ying)分層進行,每層虛鋪的厚度(du)應(ying)根據輾壓機具的性能(neng)、土(tu)質種(zhong)類、含水(shui)量和(he)施工(gong)方法(fa)等(deng)實際情況確定;
(7) 輾(zhan)(zhan)壓要沿(yan)縱(zong)向從邊向路中輾(zhan)(zhan)壓,重輾(zhan)(zhan)壓至平整(zheng)堅實為止(zhi);
(8) 地(di)基層(ceng)的質量標(biao)準:
A. 在(zai)中壓(ya)輾壓(ya)機壓(ya)過(guo)后,無顯著輪跡,無發軟(ruan)起皮,無浮土松散,波浪等現象(xiang);
B. 壓實(shi)密實(shi)度不得小于(yu)最佳密實(shi)度的95%以上;
C. 厚度允許偏差+10%;
D. 縱橫斷高程允許偏差+2CM;
E. 寬度不得小于設計寬度;
2. 級配砂石層
(1) 砂(sha)石混(hun)合料的最(zui)大粒徑不應超過砂(sha)石層的厚(hou)度(du)的2/3。塊(kuai)鋪(pu)厚(hou)度(du)應按(an)設計厚(hou)度(du)乘1.2-1.25的壓實系(xi)數(shu),如20CM厚(hou)砂(sha)石層,層厚(hou)應為(wei)24-25CM厚(hou);
(2) 攤鋪(pu)砂石要(yao)均(jun)勻一致,無粗細顆粒分離現象(xiang),砂石攤鋪(pu)長度在(zai)30-50米,開(kai)始潑(po)水(shui),用量與(yu)氣溫(wen)干濕度及砂石材料(liao)(liao)中含水(shui)量有關,要(yao)使全部砂石濕潤為好,潑(po)水(shui)后待表面稍微干,保持濕潤,輾壓至混合料(liao)(liao)不松(song)動為止。如發現有砂窩和(he)梅花現象(xiang),應將多余的(de)砂石挖出,分別滲入適量的(de)砂石或砂進(jin)行處理。
(3) 砂石層的(de)質量(liang)標準:
A、 壓實密度達到2.30KG/公(gong)升以上;
B、 厚度允許偏差+10%;
C、 縱橫斷高程允許偏差+2CM;
D、 寬(kuan)度不得(de)小于設(she)計寬(kuan)度;
E、 外觀:表面(mian)平整密(mi)度,無砂窩,梅花等現象;
F、 重(zhong)型輾(zhan)壓軌跡深度不大于5MM;
3. 碎石層
(1) 碎石(shi)層(ceng)厚度為100-120MM,其徑粒一般可(ke)在(zai)25-65MM范圍內,但不(bu)要超(chao)過(guo)墊層(ceng)厚度的2/3,采用(yong)質(zhi)地堅韌、耐磨(mo)強度均(jun)勻一致的碎花崗石(shi)或石(shi)灰,軟硬(ying)不(bu)同的石(shi)料不(bu)能摻(chan)用(yong)。碎石(shi)形狀應為多菱(ling)角(jiao)塊(kuai)體,清潔無(wu)土,不(bu)含石(shi)粉及風化(hua)雜質(zhi)等。
(2) 灘鋪碎石(shi)應(ying)按(an)虛鋪厚(hou)度(du)一次(ci)上條,避免多(duo)次(ci)找補(bu),虛鋪厚(hou)度(du)按(an)設計厚(hou)度(du)乘壓實(shi)系數1.30-1.40,已攤(tan)鋪平的碎石(shi),大小顆粒要均勻分布,厚(hou)度(du)要一致,輾壓前應(ying)斷絕交通,保持清(qing)潔;
(3) 輾(zhan)(zhan)(zhan)(zhan)(zhan)(zhan)壓(ya)(ya)(ya)(ya)以先慢后快,輾(zhan)(zhan)(zhan)(zhan)(zhan)(zhan)型以先輕后重(zhong)為(wei)原則(ze),輾(zhan)(zhan)(zhan)(zhan)(zhan)(zhan)壓(ya)(ya)(ya)(ya)輪(lun)跡應(ying)(ying)有(you)重(zhong)疊,自路邊(bian)開始向中央移動,路邊(bian)應(ying)(ying)仔細重(zhong)復(fu)的(de)輾(zhan)(zhan)(zhan)(zhan)(zhan)(zhan)壓(ya)(ya)(ya)(ya),避(bi)免石(shi)料(liao)向外擠(ji)動,輾(zhan)(zhan)(zhan)(zhan)(zhan)(zhan)壓(ya)(ya)(ya)(ya)前先灑(sa)水(shui)(shui)約3-4KG/平(ping)(ping)方,先用6-8噸輾(zhan)(zhan)(zhan)(zhan)(zhan)(zhan)壓(ya)(ya)(ya)(ya)機輾(zhan)(zhan)(zhan)(zhan)(zhan)(zhan)壓(ya)(ya)(ya)(ya)穩定(ding)碎(sui)(sui)(sui)(sui)石(shi),輾(zhan)(zhan)(zhan)(zhan)(zhan)(zhan)壓(ya)(ya)(ya)(ya)2-3遍進行找補(bu)。完成(cheng)后,換(huan)用10-12噸輾(zhan)(zhan)(zhan)(zhan)(zhan)(zhan)壓(ya)(ya)(ya)(ya)機繼續輾(zhan)(zhan)(zhan)(zhan)(zhan)(zhan)壓(ya)(ya)(ya)(ya),隨壓(ya)(ya)(ya)(ya)隨灑(sa)水(shui)(shui),每次(ci)用水(shui)(shui)量不(bu)大于1KG/平(ping)(ping)方。為(wei)使用中型輾(zhan)(zhan)(zhan)(zhan)(zhan)(zhan)壓(ya)(ya)(ya)(ya)機穩定(ding)碎(sui)(sui)(sui)(sui)石(shi)時(shi),應(ying)(ying)采(cai)用“減低(di)輾(zhan)(zhan)(zhan)(zhan)(zhan)(zhan)速(su)”,提前灑(sa)水(shui)(shui)等措(cuo)施防止(zhi)碎(sui)(sui)(sui)(sui)石(shi)棱(leng)(leng)角過(guo)(guo)(guo)多(duo)(duo)破(po)壞,如(ru)(ru)發現碎(sui)(sui)(sui)(sui)石(shi)呈圓形和形成(cheng)過(guo)(guo)(guo)多(duo)(duo)石(shi)屑,即表明(ming)“過(guo)(guo)(guo)輾(zhan)(zhan)(zhan)(zhan)(zhan)(zhan)”,應(ying)(ying)將(jiang)過(guo)(guo)(guo)輾(zhan)(zhan)(zhan)(zhan)(zhan)(zhan)部分碎(sui)(sui)(sui)(sui)石(shi)挖出,篩出細小(xiao)石(shi)料(liao),摻加(jia)帶有(you)棱(leng)(leng)角的(de)新石(shi)料(liao),再(zai)(zai)行輾(zhan)(zhan)(zhan)(zhan)(zhan)(zhan)壓(ya)(ya)(ya)(ya)。在輾(zhan)(zhan)(zhan)(zhan)(zhan)(zhan)壓(ya)(ya)(ya)(ya)過(guo)(guo)(guo)程中應(ying)(ying)隨時(shi)檢查,發現高低(di)不(bu)平(ping)(ping)現象,高處(chu)(chu)應(ying)(ying)扒松(song)整平(ping)(ping),抵處(chu)(chu)應(ying)(ying)將(jiang)表面石(shi)子扒松(song)添加(jia)相(xiang)同碎(sui)(sui)(sui)(sui)石(shi)補(bu)平(ping)(ping)后再(zai)(zai)進行壓(ya)(ya)(ya)(ya)實(shi);(4) 如(ru)(ru)碎(sui)(sui)(sui)(sui)石(shi)顆粒(li)(li)較大,而表面縫隙(xi)過(guo)(guo)(guo)大時(shi),可再(zai)(zai)鋪撒一層鑲(xiang)縫石(shi)料(liao),其粒(li)(li)徑可為(wei)5-20MM。鑲(xiang)縫石(shi)料(liao)應(ying)(ying)鑲(xiang)如(ru)(ru)碎(sui)(sui)(sui)(sui)石(shi)的(de)縫隙(xi)中,不(bu)應(ying)(ying)形成(cheng)單獨一層,輾(zhan)(zhan)(zhan)(zhan)(zhan)(zhan)壓(ya)(ya)(ya)(ya)至碎(sui)(sui)(sui)(sui)石(shi)與鑲(xiang)縫材料(liao)緊(jin)結合,而無輾(zhan)(zhan)(zhan)(zhan)(zhan)(zhan)印為(wei)止(zhi),壓(ya)(ya)(ya)(ya)實(shi)密度達(da)到2.2噸/平(ping)(ping)方;
(5) 碎石層的質量標準:
A. 壓實密度達到2.1KG/公升以上;
B. 厚度允許偏差+10%;
C. 縱橫斷高程允許偏差+2CM;
D. 寬度不得(de)小于(yu)設(she)計寬度;
E. 外觀:表面平整密實,無砂窩,梅花等想象;