论文部分内容阅读
为研究软土地区盾构端头水平冻结加固计算方法和施工技术,本文以南京某盾构区间端头为例,研究了盾构端头水平冻结加固计算及冻结关键技术。得到以下成果:采取密集布置、短时水平冻结的措施达到了理想的加固效果;按单管冻结公式推算的冻结时间和温度可满足冻结需要,但与实际冻结过程相比略显保守,冻结管布置和冻结时间在理论计算基础上仍有优化空间;冻结及强制解冻过程并严格对应,强制解冻能消除约60%的冻胀量,但无法全部消除;不同地层冻结效果差异显著,含水量大、透水性好的地层更适合冻结法加固。
In order to study the calculation method and construction technology of horizontal freezing reinforcement in the soft soil area, taking the end of a shield in Nanjing as an example, this paper studies the calculation of the horizontal freezing reinforcement and the key technologies of freezing. The results are as follows: The intensive arrangement and short-term horizontal freezing method achieve the ideal reinforcement effect. The freezing time and temperature calculated by the single tube freezing formula can meet the freezing requirement, but are slightly conservative compared with the actual freezing process. The freezing tube The layout and the freezing time still have the optimization space based on the theoretical calculation. The freezing and forced thawing processes are strictly corresponded. Forced thawing can eliminate about 60% of the frost heaving volume, but can not be completely eliminated. The freezing effect of different strata is significantly different, and the water content is large , Good permeability of the strata more suitable for freezing method to reinforce.