Influencing Parameters on the Dewatering Behavior of Annular Gap Grouts

The annular gap between segment lining and bedrock, caused by tunnel driving, must be filled instantaneously with an adequate grouting mortar. The decisive requirements for such grouts are, on the one hand, optimal flow properties lasting for several hours and sufficient stability and, on the other hand, a rapid development of shear strength immediately after grouting. The latter is normally achieved by dewatering under pressurization into the surrounding soil. Thus, two contradictory requirements are demanded for such grouts. The dewatering behavior of these grouts, which is significantly influenced by their constituents, is an important key factor. The correlation of these properties has been studied in systematic and extensive tests. The comprised grout mixtures are also performed in accordance with real design concepts to ensure an adequate application in practice. For this purpose, a test set-up was developed, simulating the conditions within annular gaps up to 18 cm in width. The amount of filterable water, including temporal effects, has been determined. Additionally, the development of shear strength by the dewatering effect has been examined at dewatered grouts. The investigations were carried out on typical grout mixtures with different variations of parameters (e.g. fly ash: additive ratio). From the results, the main influencing parameters on the dewatering behavior and development of shear strength could be defined. Consequently, well-proved mixtures can be recommended for further purpose.


  • English

Media Info

  • Media Type: Web
  • Pagination: pp 419-428
  • Monograph Title: Tunneling and Underground Construction

Subject/Index Terms

Filing Info

  • Accession Number: 01531624
  • Record Type: Publication
  • ISBN: 9780784413449
  • Files: TRIS, ASCE
  • Created Date: Jul 25 2014 4:16PM