【摘要】 引洮供水一期工程总干渠7号隧洞中下游两段总长78.65 m、埋深135.0～206.0 m洞段穿越新近系含水疏松粉(细)砂极软岩地层,采用"洞内水平冻结法"掘进。为掌握深埋地层冻结设计与施工技术,结合工程实践,对极软岩工程地质特性,以及"水平冻结法"设计、温度场、制冷系统与施工等关键技术进行了研究。冻结壁厚不小于2.0 m,均温-10℃,冻结孔35～40 d交圈,积极冻结时间40～50 d,循环盐水温度-28℃。圆形断面双圈发散布设冻结孔,类马蹄形断面洞段三循环冻结,掌子面及后方加强2个冻结孔布孔断面,掌子面双圈孔,内圈类马蹄形水平布孔,外圈及单圈加强断面发散布孔,圆形开孔,前方远端类马蹄形,总孔数229个,冻结管总长5.02 km。"水平冻结法"掘进全面成功,安全通过极软岩地层,取得重大技术突破与创新,填补了国内200.0 m以上深埋隧洞(隧道与巷道)洞内"水平冻结"工法技术的空白,开创了国内深埋水工隧洞"冻结法"施工技术的先导开端,标志着我国地下工程建设"冻结法"设计与施工技术全面跃上新台阶。更多还原

【Abstract】 The total length of the middle and lower reaches of the main canal in the first phase of Yintao Diversion Water Supply Project is 78.65 m and the buried depth is from 135.0 m to 206.0 m. The tunnel passes through the Neogene water-bearing loose silt(fine) sand and extremely soft rock strata, and the "horizontal freezing method in the hole" is excavated. For the purpose of deep buried strata freezing design and construction technology, combined with engineering practice, this paper studied the engineering geological characteristics of very soft rock, as well as the key techniques of "horizontal freezing method" design, temperature field, refrigeration system and construction, etc. The freezing wall thickness was not less than 2.0 m, the mean temperature was -10.0 ℃, the freezing hole was 35-40 days circle, the active freezing time was 40-50 days, the circulating salt water temperature was -28 ℃. Freezing holes were distributed in double circles of circular section, three cycle freezing in the section of horseshoe type section, two frozen holes in palm face and rear reinforcement, double circle holes in palm surface, horizontal holes in horseshoe type in inner circle, The outer ring and single ring reinforced cross section had scattered holes, circular openings, horseshoe type at the distal end of the front, the total number of holes was 229 and the total length of the freezing tube was 5.02 km. The "horizontal freezing method" had been successfully excavated in an all round way, safely passed through the very soft rock strata, made great technical breakthroughs and innovations and filled the blank of "horizontal freezing" technique in the deep buried tunnels(tunnels and tunnels) above 200.0 m in our country. The construction technology of "freezing method" for deep buried hydraulic tunnel in China has been pioneered, which indicates that the design and construction technology of "freezing method" for underground engineering construction in our country has leapt to a new level in an all-round way.更多还原