Injection Treatment for Tunneling Excavation in Sandy Soils with High Fines Content
Instability and high permeability are two of the problems facing tunnelling excavations in soils with high fines content. Among the different techniques used to improve these soils, the injection of cement grouts stands out. In this work, a grouting treatment is designed to ensure the stability of t...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-10-01
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| Series: | Energies |
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| Online Access: | https://www.mdpi.com/1996-1073/14/21/6930 |
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| author | Johnatan González-García Celestino González-Nicieza Martina-Inmaculada Álvarez-Fernández María-Belén Prendes-Gero |
| author_facet | Johnatan González-García Celestino González-Nicieza Martina-Inmaculada Álvarez-Fernández María-Belén Prendes-Gero |
| author_sort | Johnatan González-García |
| collection | DOAJ |
| description | Instability and high permeability are two of the problems facing tunnelling excavations in soils with high fines content. Among the different techniques used to improve these soils, the injection of cement grouts stands out. In this work, a grouting treatment is designed to ensure the stability of the ground during the construction of two tunnels linking two municipalities in the north of Spain in Biscay, and to reduce the inflow of water from the aquifer located in the vicinity of these tunnels. First of all, the rock mass is analysed and the material to be injected is selected on the basis of the authors’ experience as well as setting time and compressive strength. Subsequently, with a test device designed by the DinRock research group of the University of Oviedo, two types of laboratory tests are carried out in order to analyse the effect of fines migration and washing on the water flows and the effect of re-injections of grouts with different densities on the permeability value. The results show that, in sandy materials, obtaining high degrees of waterproofing together with large stable zones can only be achieved by a combination of treatments and stages with different materials and densities. In addition, maximum values for both injection pressure and flow rate must be established depending on the type of grout and the permeability of the soil. Once the problem has been analysed, the injection treatment is designed and executed. The treatment consists of one pre-injection in four stages with 30 boreholes drilled in the top heading, 19–20 boreholes drilled in the bench, and one post-injection with boreholes drilled around the perimeter of the tunnel in those areas where the pre-injection does not achieve the desired degree of waterproofing. |
| first_indexed | 2024-03-10T06:03:48Z |
| format | Article |
| id | doaj.art-9019367abc7c41be986c43ea7c01eb7b |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-03-10T06:03:48Z |
| publishDate | 2021-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj.art-9019367abc7c41be986c43ea7c01eb7b2023-11-22T20:41:04ZengMDPI AGEnergies1996-10732021-10-011421693010.3390/en14216930Injection Treatment for Tunneling Excavation in Sandy Soils with High Fines ContentJohnatan González-García0Celestino González-Nicieza1Martina-Inmaculada Álvarez-Fernández2María-Belén Prendes-Gero3Perforaciones Noroeste, S.A., 33002 Oviedo, SpainDinRock Group, University of Oviedo, 33003 Oviedo, SpainDinRock Group, University of Oviedo, 33003 Oviedo, SpainDinRock Group, University of Oviedo, 33003 Oviedo, SpainInstability and high permeability are two of the problems facing tunnelling excavations in soils with high fines content. Among the different techniques used to improve these soils, the injection of cement grouts stands out. In this work, a grouting treatment is designed to ensure the stability of the ground during the construction of two tunnels linking two municipalities in the north of Spain in Biscay, and to reduce the inflow of water from the aquifer located in the vicinity of these tunnels. First of all, the rock mass is analysed and the material to be injected is selected on the basis of the authors’ experience as well as setting time and compressive strength. Subsequently, with a test device designed by the DinRock research group of the University of Oviedo, two types of laboratory tests are carried out in order to analyse the effect of fines migration and washing on the water flows and the effect of re-injections of grouts with different densities on the permeability value. The results show that, in sandy materials, obtaining high degrees of waterproofing together with large stable zones can only be achieved by a combination of treatments and stages with different materials and densities. In addition, maximum values for both injection pressure and flow rate must be established depending on the type of grout and the permeability of the soil. Once the problem has been analysed, the injection treatment is designed and executed. The treatment consists of one pre-injection in four stages with 30 boreholes drilled in the top heading, 19–20 boreholes drilled in the bench, and one post-injection with boreholes drilled around the perimeter of the tunnel in those areas where the pre-injection does not achieve the desired degree of waterproofing.https://www.mdpi.com/1996-1073/14/21/6930tunnelling excavationinjection treatmentcement groutingground stabilitywaterproofing |
| spellingShingle | Johnatan González-García Celestino González-Nicieza Martina-Inmaculada Álvarez-Fernández María-Belén Prendes-Gero Injection Treatment for Tunneling Excavation in Sandy Soils with High Fines Content Energies tunnelling excavation injection treatment cement grouting ground stability waterproofing |
| title | Injection Treatment for Tunneling Excavation in Sandy Soils with High Fines Content |
| title_full | Injection Treatment for Tunneling Excavation in Sandy Soils with High Fines Content |
| title_fullStr | Injection Treatment for Tunneling Excavation in Sandy Soils with High Fines Content |
| title_full_unstemmed | Injection Treatment for Tunneling Excavation in Sandy Soils with High Fines Content |
| title_short | Injection Treatment for Tunneling Excavation in Sandy Soils with High Fines Content |
| title_sort | injection treatment for tunneling excavation in sandy soils with high fines content |
| topic | tunnelling excavation injection treatment cement grouting ground stability waterproofing |
| url | https://www.mdpi.com/1996-1073/14/21/6930 |
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