研究目的:通过对4种联络通道施工方法的特点、风险性等方面的分析与比较,提出地下工程富水砂层的联络通道首选施工工法;提出其设计与施工的关键控制措施,以确保施工的质量和安全。
研究结论:处于富水砂层中的联络通道施工,冻结法由于具有可靠性高,对地下水、土层无污染等优点,是施工方法的首选。为了保证冻结法成功、安全实施,必须考虑联络通道洞口处管片的特殊设计;为了减轻冻土膨胀对隧道的影响,在隧道内设置内支撑可有效控制隧道变形;冻结施工过程中应采用应急措施,如安装安全门等措施避免发生施工意外;土体冻胀和融沉阶段采取卸压孔、热水循环及跟踪注浆等控制措施是非常有效的。
Research purposes: Through analyses and comparisons of the construction characteristics and dangers of four construction methods for the connecting passage in water-enriched sand bed, the construction method and control measures related to the design and construction are offered for construction of the underground connecting passage in water-enriched sand bed to guarantee the construction quality and safety.
Research conclusions: For construction of the connecting passage in water-enriched sand bed, the artificial ground freezing method is a prior construction method featured with high reliability and no pollution of groundwater and ground. Moreover, in order to ensure the successful and safe application of the artificial ground freezing method, the duct piece at the tunnel portal of the connecting passage should be designed specially. In order to reduce the impact of expansive soil on the tunnel, the internal support should be installed in the tunnel to effectively control the tunnel deformation. The special measures should be taken in the process of freezing, such as installation of safe door to prevent the appearance of accident. In addition, to install pressure-releasing holes and use heat -cycling and trace grouting methods are effective.