水下联络通道积极冻结参数现场实测变化规律

Variation Law of Field Measured Values of Positive Freezing Parameters of Underwater Connecting Channel

由于水下联络通道处于高水压、高透水及水力联系强等复杂环境下,相比于陆域联络通道,施工风险更大.以上海某隧道水下联络通道冻结施工工程为依托,根据现场实测数据,研究了水下联络通道积极冻结期间各项指标随冻结时间的变化规律.结论如下:①盐水温度稳定在-28℃左右,且去路及回路温差基本保持在2℃,测温孔内温度随着冻结时间持续下降,最终基本保持在-15℃;②卸压孔内压力均在泄压时出现快速增长现象,孔内最高压力为0.65 MPa左右;③管片及土体界面处1.1 m范围内温度基本处于-12℃以下,冻结帷幕发展良好;④冻结引起右线隧道出现轻微隆起变形,最大变形量为4.45 mm,左线隧道出现沉降变形,最大下沉量为-5.39 mm,联络通道处于较稳定状态.通过水下联络通道实测获得的数据变化规律,可以用于指导类似水下联络通道冻结工程的设计和施工.

The construction of underwater connecting channel is under the complicated environment of soft soil,high water pressure,permeable water and strong hydraulic connection.In this paper,based on a underwater connecting channel frozen reinforcement construction engineering,according to the measured data,we analyzed the indicators changing rule with the the freezing time during active freeze period,and got the main conclusions as follows.Brine temperature is stably around-28℃,and the incoming and outgoing temperature difference maintains in the 2℃.The temperature within the thermometer hole declines with the freezing time,ultimately keeps at 15℃;The pressure inside the pressure relief hole rises rapidly during pressure relief,and the maximum pressure inside the hole is about 0.65 MPa.The temperature at the interface of the pipe and soil within 1.1 m is generally below-12℃,and the freezing curtain develops well.The right line tunnel has slight uplift deformation with the maximum deformation of 4.45 mm,while the left line tunnel has subsidence phenomenon with the maximum subsidence of-5.39 mm.The connecting channel is in a relatively stable state.The variation rules obtained from the actual measurement of underwater connecting channel can be used to guide the design and construction of similar projects.