四、跑道基礎施工規范:
1. 地基
(1) 一(yi)般較(jiao)好(hao)的土,可直接壓(ya)實或夯實即可;
(2) 下沉性大(da)的和(he)含水量大(da),松軟(ruan)呈橡皮狀(zhuang)的土,必須更換和(he)加(jia)固,腐植土不能做為基土,應(ying)進行更換;
(3) 在結(jie)冰(bing)地區,地基表(biao)面應在冰(bing)結(jie)線以(yi)下(xia),以(yi)防凍膠破壞(huai)朔膠面層;
(4) 基(ji)土過(guo)干或過(guo)濕(shi)應適當加水或曬干,以達(da)到(dao)壓(ya)實最佳含水率(lv)為宜(yi);
(5) 用碎卵石(shi)或磚等作基土表面(mian)處(chu)理時,宜采用粒徑為40-60MM的塊料(liao),壓入深度不應(ying)小于40MM;
(6) 基(ji)土如(ru)需要更換時(shi),應分層(ceng)進行(xing),每層(ceng)虛鋪的厚度(du)應根(gen)據輾(zhan)壓機(ji)具的性能、土質種類、含水(shui)量(liang)和施(shi)工(gong)方法等實(shi)際情況確定;
(7) 輾(zhan)壓要(yao)沿縱向從(cong)邊向路中輾(zhan)壓,重輾(zhan)壓至(zhi)平整堅(jian)實為止(zhi);
(8) 地基層的質量(liang)標準:
A. 在(zai)中壓(ya)輾壓(ya)機壓(ya)過后,無顯著(zhu)輪跡,無發軟起皮,無浮土(tu)松散,波浪(lang)等現象;
B. 壓實(shi)(shi)密實(shi)(shi)度(du)不(bu)得小于最佳密實(shi)(shi)度(du)的(de)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(yu)設計寬度;
2. 級配砂石層
(1) 砂(sha)(sha)石混合料的(de)(de)(de)最大(da)粒(li)徑(jing)不應超過(guo)砂(sha)(sha)石層(ceng)的(de)(de)(de)厚(hou)度的(de)(de)(de)2/3。塊鋪厚(hou)度應按(an)設計厚(hou)度乘1.2-1.25的(de)(de)(de)壓(ya)實系數(shu),如(ru)20CM厚(hou)砂(sha)(sha)石層(ceng),層(ceng)厚(hou)應為24-25CM厚(hou);
(2) 攤鋪砂(sha)石(shi)(shi)(shi)要(yao)(yao)均勻一(yi)致,無粗細顆(ke)粒分(fen)離(li)現(xian)象(xiang),砂(sha)石(shi)(shi)(shi)攤鋪長度(du)在30-50米,開始潑水,用(yong)量與氣(qi)溫干(gan)(gan)濕度(du)及(ji)砂(sha)石(shi)(shi)(shi)材料中(zhong)含水量有關,要(yao)(yao)使全(quan)部砂(sha)石(shi)(shi)(shi)濕潤(run)為(wei)好,潑水后待表面稍微干(gan)(gan),保持(chi)濕潤(run),輾壓至(zhi)混合料不松動為(wei)止。如發現(xian)有砂(sha)窩(wo)和梅(mei)花現(xian)象(xiang),應將(jiang)多余的(de)砂(sha)石(shi)(shi)(shi)挖出,分(fen)別滲入適(shi)量的(de)砂(sha)石(shi)(shi)(shi)或砂(sha)進行處理(li)。
(3) 砂石層的質(zhi)量標(biao)準:
A、 壓實密度(du)達到2.30KG/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(kuan)度(du)不得(de)小于設計寬(kuan)度(du);
E、 外(wai)觀:表面平整(zheng)密度,無砂窩,梅花(hua)等現(xian)象;
F、 重型輾壓軌(gui)跡深度不大(da)于5MM;
3. 碎石層
(1) 碎石(shi)層(ceng)厚度(du)為(wei)100-120MM,其徑粒一般(ban)可在25-65MM范(fan)圍內(nei),但不(bu)要超(chao)過墊(dian)層(ceng)厚度(du)的2/3,采用質地堅韌、耐磨強度(du)均勻一致的碎花崗石(shi)或石(shi)灰,軟硬不(bu)同的石(shi)料(liao)不(bu)能摻用。碎石(shi)形狀應為(wei)多菱角塊體,清潔(jie)無土,不(bu)含石(shi)粉及(ji)風(feng)化雜質等。
(2) 灘鋪碎石(shi)應按虛鋪厚(hou)度(du)一次(ci)上條,避免多次(ci)找補,虛鋪厚(hou)度(du)按設計厚(hou)度(du)乘壓實(shi)系數1.30-1.40,已攤鋪平(ping)的(de)碎石(shi),大小顆(ke)粒要均勻分布,厚(hou)度(du)要一致,輾壓前應斷(duan)絕交通,保(bao)持清潔;
(3) 輾(zhan)(zhan)(zhan)(zhan)壓(ya)(ya)(ya)(ya)(ya)以先慢后(hou)快,輾(zhan)(zhan)(zhan)(zhan)型(xing)以先輕后(hou)重為原則,輾(zhan)(zhan)(zhan)(zhan)壓(ya)(ya)(ya)(ya)(ya)輪跡應(ying)有(you)重疊(die),自路邊(bian)開始向中(zhong)央移動,路邊(bian)應(ying)仔(zi)細重復的輾(zhan)(zhan)(zhan)(zhan)壓(ya)(ya)(ya)(ya)(ya),避免石(shi)(shi)(shi)料向外擠(ji)動,輾(zhan)(zhan)(zhan)(zhan)壓(ya)(ya)(ya)(ya)(ya)前(qian)先灑水約3-4KG/平(ping)(ping)方(fang)(fang),先用(yong)(yong)6-8噸(dun)輾(zhan)(zhan)(zhan)(zhan)壓(ya)(ya)(ya)(ya)(ya)機輾(zhan)(zhan)(zhan)(zhan)壓(ya)(ya)(ya)(ya)(ya)穩定碎(sui)石(shi)(shi)(shi),輾(zhan)(zhan)(zhan)(zhan)壓(ya)(ya)(ya)(ya)(ya)2-3遍進行找補。完成(cheng)后(hou),換用(yong)(yong)10-12噸(dun)輾(zhan)(zhan)(zhan)(zhan)壓(ya)(ya)(ya)(ya)(ya)機繼(ji)續輾(zhan)(zhan)(zhan)(zhan)壓(ya)(ya)(ya)(ya)(ya),隨(sui)壓(ya)(ya)(ya)(ya)(ya)隨(sui)灑水,每次用(yong)(yong)水量(liang)不大于1KG/平(ping)(ping)方(fang)(fang)。為使用(yong)(yong)中(zhong)型(xing)輾(zhan)(zhan)(zhan)(zhan)壓(ya)(ya)(ya)(ya)(ya)機穩定碎(sui)石(shi)(shi)(shi)時,應(ying)采用(yong)(yong)“減(jian)低輾(zhan)(zhan)(zhan)(zhan)速”,提前(qian)灑水等措施防止碎(sui)石(shi)(shi)(shi)棱角過(guo)多破(po)壞,如發現(xian)碎(sui)石(shi)(shi)(shi)呈(cheng)圓(yuan)形和形成(cheng)過(guo)多石(shi)(shi)(shi)屑,即(ji)表明“過(guo)輾(zhan)(zhan)(zhan)(zhan)”,應(ying)將過(guo)輾(zhan)(zhan)(zhan)(zhan)部分碎(sui)石(shi)(shi)(shi)挖出,篩出細小石(shi)(shi)(shi)料,摻(chan)加帶有(you)棱角的新石(shi)(shi)(shi)料,再行輾(zhan)(zhan)(zhan)(zhan)壓(ya)(ya)(ya)(ya)(ya)。在輾(zhan)(zhan)(zhan)(zhan)壓(ya)(ya)(ya)(ya)(ya)過(guo)程中(zhong)應(ying)隨(sui)時檢查,發現(xian)高(gao)(gao)低不平(ping)(ping)現(xian)象,高(gao)(gao)處(chu)(chu)應(ying)扒松整平(ping)(ping),抵處(chu)(chu)應(ying)將表面石(shi)(shi)(shi)子扒松添加相同(tong)碎(sui)石(shi)(shi)(shi)補平(ping)(ping)后(hou)再進行壓(ya)(ya)(ya)(ya)(ya)實(shi);(4) 如碎(sui)石(shi)(shi)(shi)顆粒較(jiao)大,而表面縫隙過(guo)大時,可再鋪撒一(yi)層鑲(xiang)縫石(shi)(shi)(shi)料,其粒徑可為5-20MM。鑲(xiang)縫石(shi)(shi)(shi)料應(ying)鑲(xiang)如碎(sui)石(shi)(shi)(shi)的縫隙中(zhong),不應(ying)形成(cheng)單獨(du)一(yi)層,輾(zhan)(zhan)(zhan)(zhan)壓(ya)(ya)(ya)(ya)(ya)至(zhi)碎(sui)石(shi)(shi)(shi)與鑲(xiang)縫材料緊結合(he),而無輾(zhan)(zhan)(zhan)(zhan)印為止,壓(ya)(ya)(ya)(ya)(ya)實(shi)密度(du)達到2.2噸(dun)/平(ping)(ping)方(fang)(fang);
(5) 碎石層的質量標準:
A. 壓實密度達(da)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(du)不得(de)小于(yu)設計寬度(du);
E. 外觀:表面平整密實,無砂窩,梅花等想象;