


作者簡介:李洋(1990-),男,碩士,工程師。研究方向為水利工程檢測。
DOI:10.19981/j.CN23-1581/G3.2024.21.046
摘" 要:該文以某水利樞紐工程為例,探究特大斷面導流隧洞施工中爆破開挖與錨噴掛網聯合支護技術的應用。經前期地質勘察可知,隧洞圍巖為Ⅱ~Ⅲ級,圍巖穩定性較好,采取先進行光面爆破再進行洞身開挖的作業方案。在清運碴石、清除危石后,在開挖面上初噴混凝土形成穩定工作面。然后打入錨桿、掛鋼筋網并進行二次襯砌,對導流隧洞支護,營造安全的施工環境。拱頂沉降監測數據表明,在導流隧洞開挖后的30 d內,每日平均沉降速率為2.09 mm,在允許范圍之內,本次特大斷面導流隧洞施工效果符合預期。
關鍵詞:水利樞紐工程;導流隧洞;錨桿支護;回填灌漿;混凝土
中圖分類號:TV544" " "文獻標志碼:A" " " " " 文章編號: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
在水利工程建設中,特大斷面導流隧洞的開挖作業會對圍巖產生擾動,有概率出現圍巖變形、拱頂塌陷以及隧洞內滲水等一系列問題,不僅影響正常的施工進度,而且還會對隧洞內施工人員的安全構成威脅。因此,在特大斷面導流隧洞施工前,必須要綜合采取物理、化學等方法進行地質探測,了解施工區域的地層結構、巖土特性和地下水賦存情況,在此基礎上設計科學的施工方案。在圍巖穩定的情況下,可采取爆破開挖方式,降低隧洞掘進難度、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措施。錨噴掛網聯合支護在提高圍巖穩定性、防止拱頂冒落事故的基礎上,還有防滲作用,成為特大斷面導流隧洞施工中的常用技術?!?br>