双排管冻结土帷幕厚度的测点位置敏感度分析

Sensitivity Analysis on Position of Temperature Measuring Points of Bakholdin Solution in Double-Row-Pipe Freezing

冻土帷幕厚度是冻结法施工过程中人为进行冻结控制的重要参考因素。施工中常采用巴霍尔金公式根据现场实测的测温点温度数据,结合温度场公式来反算冻土帷幕厚度。本文基于双排管巴霍尔金公式,对测温点位置的变化对冻土帷幕厚度的影响进行敏感度分析。理论分析结果表明,测温点布置在主面上靠近冻土帷幕边缘和双排管之间的中心附近位置时能得到比较准确计算结果(本文仅从理论上对测温点位置变化对帷幕厚度影响进行分析,工程实际一般不在双排管之间布置测温点);界面上与主面上的误差变化规律基本相同,且误差相对主面来说更小。故根据本文的计算结果,将测温点布置在界面上靠近冻土帷幕边缘和双排管之间的中心位置,能够使测温点位置对冻土帷幕厚度的推算误差影响最小,有利于保证工程施工质量和安全。

Thickness of frozen soil is an important control parameter in the process of construction using freezing method. During the construction, according to the site measured temperature data and the layout of the freezing holes, Bakholdin formula was used to calculate the thickness ot＇ frozen soil. Based on the Bakholdin formula in doub- le-row-pipe freezing, the sensitivity analysis was conducted on the influence of the location of temperature measuring points on the frozen soil thickness in Bakholdin model. The results showed that： in the main section when temperature measuring points were arranged near the boundary of the frozen soil or at the middle of the two-row-pipe, more accu- rate results were obtained ; The test result of the intersection section is related to that of the main section, but the cal- culation error is less in the intersection section. Based on the result of sensitivity analysis, in order to obtain more ac- curate results, the temperature measuring points should be arranged near the boundary of the frozen soil or at the mid- die of the two-row-pipe in the intersection section, so as to ensure the quality and safety of the construction of the pro- ject.