無砂管工作原理

鋼(gang)筋混凝土之所以(yi)可以(yi)共(gong)同(tong)(tong)工作是由它(ta)自身的(de)(de)材料性質決定的(de)(de)。首先鋼(gang)筋與(yu)混凝土有(you)著近似相同(tong)(tong)的(de)(de)線膨脹系數，不會由環(huan)境不同(tong)(tong)產生過大的(de)(de)應力(li)。其次鋼(gang)筋與(yu)混凝土之間(jian)有(you)良好(hao)的(de)(de)粘(zhan)結(jie)力(li)，有(you)時鋼(gang)筋的(de)(de)表面也被加工成有(you)間(jian)隔(ge)的(de)(de)肋條（稱為(wei)變(bian)形鋼(gang)筋）來提高(gao)混凝土與(yu)鋼(gang)筋之間(jian)的(de)(de)機械咬合(he)，當此仍不足(zu)以(yi)傳遞鋼(gang)筋與(yu)混凝土之間(jian)的(de)(de)拉力(li)時，通常(chang)將鋼(gang)筋的(de)(de)端(duan)部彎起180度彎鉤。此外混凝土(tu)中的氫氧化鈣(gai)提供(gong)的堿性(xing)環(huan)境，在鋼(gang)筋(jin)表面形成了(le)一層鈍化保護膜，使鋼(gang)筋(jin)相對于中性(xing)與(yu)酸性(xing)環(huan)境下更不易(yi)腐蝕。

無砂管質(zhi)量控制(zhi)

在(zai)施工階段，控制的要點就是嚴格按照審批通過(guo)的“施工(gong)組織設計”和“施工方(fang)案”進(jin)行施(shi)工(gong)(gong)(gong)(gong)控制(zhi)，并(bing)做(zuo)好(hao)關鍵工(gong)(gong)(gong)(gong)序工(gong)(gong)(gong)(gong)程(cheng)(cheng)、隱蔽(bi)工(gong)(gong)(gong)(gong)程(cheng)(cheng)驗收(shou)，閉水試驗及涂裝施(shi)工(gong)(gong)(gong)(gong)的(de)(de)(de)(de)質(zhi)量檢驗工(gong)(gong)(gong)(gong)作(zuo)(zuo)(zuo)。由于頂(ding)管(guan)(guan)(guan)工(gong)(gong)(gong)(gong)藝(yi)的(de)(de)(de)(de)特殊性，在施(shi)工(gong)(gong)(gong)(gong)過程(cheng)(cheng)中，重點(dian)做(zuo)好(hao)以(yi)下(xia)(xia)(xia)(xia)內(nei)容的(de)(de)(de)(de)控制(zhi)；工(gong)(gong)(gong)(gong)作(zuo)(zuo)(zuo)井(jing)作(zuo)(zuo)(zuo)為頂(ding)管(guan)(guan)(guan)機的(de)(de)(de)(de)工(gong)(gong)(gong)(gong)作(zuo)(zuo)(zuo)場地(di)(di)，須滿足頂(ding)管(guan)(guan)(guan)過程(cheng)(cheng)中結構的(de)(de)(de)(de)穩(wen)定，且截面設(she)計須滿足頂(ding)管(guan)(guan)(guan)千(qian)斤頂(ding)、后背(bei)尺寸要求。在沉(chen)(chen)井(jing)施(shi)工(gong)(gong)(gong)(gong)過程(cheng)(cheng)中，重點(dian)監控沉(chen)(chen)井(jing)的(de)(de)(de)(de)終沉(chen)(chen)階段，尤(you)其是在地(di)(di)質(zhi)條件不好(hao)的(de)(de)(de)(de)情況下(xia)(xia)(xia)(xia)。對施(shi)工(gong)(gong)(gong)(gong)過程(cheng)(cheng)出現(xian)的(de)(de)(de)(de)問題，應(ying)及時(shi)進(jin)行分析和糾(jiu)偏，保(bao)證(zheng)沉(chen)(chen)井(jing)下(xia)(xia)(xia)(xia)沉(chen)(chen)和干(gan)封底的(de)(de)(de)(de)質(zhi)量。在頂(ding)管(guan)(guan)(guan)施(shi)工(gong)(gong)(gong)(gong)前，要作(zuo)(zuo)(zuo)好(hao)扎扎實(shi)實(shi)的(de)(de)(de)(de)技術交底和交底工(gong)(gong)(gong)(gong)作(zuo)(zuo)(zuo)。讓所有(you)施(shi)工(gong)(gong)(gong)(gong)人員除了掌握頂(ding)管(guan)(guan)(guan)操作(zuo)(zuo)(zuo)技能和注意事(shi)項外，還(huan)應(ying)掌握處置涌水、流砂等突發(fa)事(shi)的(de)(de)(de)(de)方(fang)法。必須按照設(she)定的(de)(de)(de)(de)管(guan)(guan)(guan)道中心線與頂(ding)管(guan)(guan)(guan)工(gong)(gong)(gong)(gong)作(zuo)(zuo)(zuo)井(jing)、接(jie)收(shou)井(jing)建(jian)立地(di)(di)面與地(di)(di)下(xia)(xia)(xia)(xia)測(ce)量控制(zhi)系統(tong)。當(dang)頂(ding)管(guan)(guan)(guan)頂(ding)進(jin)長(chang)度(du)較長(chang)時(shi)，必須保(bao)證(zheng)通風機械(xie)的(de)(de)(de)(de)正(zheng)常運(yun)轉，以(yi)確(que)保(bao)管(guan)(guan)(guan)內(nei)通風良好(hao)，避(bi)免。接(jie)口(kou)(kou)(kou)頂(ding)合時(shi)，應(ying)保(bao)證(zheng)平整(zheng)對中頂(ding)入，橡膠止(zhi)水圈應(ying)均勻擠壓到位(wei)，接(jie)口(kou)(kou)(kou)鋼套環或承插口(kou)(kou)(kou)管(guan)(guan)(guan)壁密貼，木墊板無松動脫(tuo)落，接(jie)口(kou)(kou)(kou)間隙均勻一致。頂(ding)管(guan)(guan)(guan)出洞前，必須進(jin)行以(yi)下(xia)(xia)(xia)(xia)的(de)(de)(de)(de)控制(zhi)，確(que)保(bao)頂(ding)管(guan)(guan)(guan)順(shun)利出洞。A對頂管整個系統的安裝，單(dan)機調試進行檢查，并進行設備聯運調試。B檢(jian)查洞(dong)口橡膠止水圈的安裝是(shi)否牢固，尺(chi)寸是(shi)否準確，是(shi)否能完全(quan)封堵機頭(tou)與洞(dong)口空隙(xi)。C檢查洞(dong)口前(qian)(qian)方的(de)土體是(shi)(shi)否正(zheng)采(cai)取(qu)了(le)加固措施，洞(dong)口前(qian)(qian)方是(shi)(shi)否建立了(le)沉降監測。機頭(tou)出洞(dong)時，頂進操作應(ying)(ying)謹慎平穩勻速推進，首(shou)節管(guan)出洞(dong)口后應(ying)(ying)立即開始均勻壓注(zhu)觸變泥(ni)漿。在管(guan)節出洞(dong)10～20m范圍內(nei)，檢查并(bing)督(du)促施工(gong)員將(jiang)切土(tu)、出泥、頂速、土(tu)壓(ya)、軸線、標高等(deng)施工(gong)參數逐(zhu)漸調整至(zhi)正(zheng)常狀態。