Evaluation of "GIN method" at Two fans of City banan project in Stockholm

Abstract: An underground installation with too much inflow can lead to dangerous consequences for around environment, therefore a well-sealed construction results in appropriate inflows. To mitigate movement of ground water table in underground constructions, it is necessary to seal the rock mass by grout injection. To fulfill the inflow requirement, cement based grouting is both practical and economical solution and is used in Sweden as permanent solution because of the good quality rock mass of Nordic countries. To achieve an effective and more economical grouting process, the method of stop criteria named GIN has been developed for underground constructions. "GIN method" is a method in formulating grouting works which provides possibility for minimizing the risk of hydro fracturing and hydro jacking in grouting process to optimize it in performance and cost of construction process. In this report the effort is testing the validity of this method in City banan project which is situated in Stockholm. Data are taken from the City banan project which is under construction by Traffikverket in Stockholm. To attain this aim, data from monitoring of grouting process was collected and Pressure and flow values were obtained and have been employed as input data in this report. After applying GIN method, results have been analyzed and discussed in detail. It has been shown that in studied cases, the theory cannot provide promising results and this method is difficult to be applicable in this project. Therefore, additional tests are needed to the exact suitable GIN number for the project.