


作者簡介:李洋(1990-),男,碩士,工程師。研究方向?yàn)樗こ虣z測。
DOI:10.19981/j.CN23-1581/G3.2024.21.046
摘" 要:該文以某水利樞紐工程為例,探究特大斷面導(dǎo)流隧洞施工中爆破開挖與錨噴掛網(wǎng)聯(lián)合支護(hù)技術(shù)的應(yīng)用。經(jīng)前期地質(zhì)勘察可知,隧洞圍巖為Ⅱ~Ⅲ級,圍巖穩(wěn)定性較好,采取先進(jìn)行光面爆破再進(jìn)行洞身開挖的作業(yè)方案。在清運(yùn)碴石、清除危石后,在開挖面上初噴混凝土形成穩(wěn)定工作面。然后打入錨桿、掛鋼筋網(wǎng)并進(jìn)行二次襯砌,對導(dǎo)流隧洞支護(hù),營造安全的施工環(huán)境。拱頂沉降監(jiān)測數(shù)據(jù)表明,在導(dǎo)流隧洞開挖后的30 d內(nèi),每日平均沉降速率為2.09 mm,在允許范圍之內(nèi),本次特大斷面導(dǎo)流隧洞施工效果符合預(yù)期。
關(guān)鍵詞:水利樞紐工程;導(dǎo)流隧洞;錨桿支護(hù);回填灌漿;混凝土
中圖分類號(hào):TV544" " "文獻(xiàn)標(biāo)志碼:A" " " " " 文章編號(hào):2095-2945(2024)21-0193-04
Abstract: Taking a water control project as an example, this paper probes into the application of blasting excavation and anchor-shotcreting net combined support technology in the construction of extra-large cross-section diversion tunnel. According to the previous geological survey, the surrounding rock of the tunnel is grades Ⅱ~Ⅲ, and the surrounding rock is stable, so the operation scheme of smooth blasting and then excavation is adopted. After removing the ballast and dangerous rock, the stable working face is formed by spraying concrete on the excavation face. Then put in the bolt, hang the steel mesh and carry on the secondary lining to support the diversion tunnel and create a safe construction environment. The monitoring data of arch roof settlement show that the average daily settlement rate is 2.09 mm within 30 days after the diversion tunnel is excavated. Within the allowable range, the construction effect of this extra-large cross-section diversion tunnel is in line with the expectation.
Keywords: water control project; diversion tunnel; bolt support; backfilling grouting; concrete
在水利工程建設(shè)中,特大斷面導(dǎo)流隧洞的開挖作業(yè)會(huì)對圍巖產(chǎn)生擾動(dòng),有概率出現(xiàn)圍巖變形、拱頂塌陷以及隧洞內(nèi)滲水等一系列問題,不僅影響正常的施工進(jìn)度,而且還會(huì)對隧洞內(nèi)施工人員的安全構(gòu)成威脅。因此,在特大斷面導(dǎo)流隧洞施工前,必須要綜合采取物理、化學(xué)等方法進(jìn)行地質(zhì)探測,了解施工區(qū)域的地層結(jié)構(gòu)、巖土特性和地下水賦存情況,在此基礎(chǔ)上設(shè)計(jì)科學(xué)的施工方案。在圍巖穩(wěn)定的情況下,可采取爆破開挖方式,降低隧洞掘進(jìn)難度、加快隧洞施工效率。為了避免拱頂沉降、圍巖變形等情況,需要在洞身開挖后采取必要的支護(hù)措施。錨噴掛網(wǎng)聯(lián)合支護(hù)在提高圍巖穩(wěn)定性、防止拱頂冒落事故的基礎(chǔ)上,還有防滲作用,成為特大斷面導(dǎo)流隧洞施工中的常用技術(shù)?!?br>