“Real Time Grouting Control Method” is a pioneer idea informulating grouting works which provides possibility for monitoring groutingprocess in real time to optimize it to performance and cost. Currently this theoryhas been tested with data from tunnels in Stockholm. In this report the effort istesting the validity of this method in a kind of geology which is situated insouthwest of Iran. Data are taken from the Gotvand dam project which is underconstruction on Karoon River. To achieve this goal, Tests are performed inStockholm by using the cement collected from the dam site to obtain rheologicaland penetrability properties of the grout mix which is in use in Gotvand project.Pressure and flow values are recorded in during grouting and have beenemployed as input data in this report. By developing a proper application, resultshave been analysed and discussed in detail. It has been shown that in studiedcases the theory can provide promising results and this method is applicable inthis project although there is a need for site investigation and testing different kindof grout mixes to precise results and be able to drive a general conclusion. / QC 20101009

The main goal of the grouting is to seal the fractures in the rock mass,improve the strength properties of the rock mass and decrease deformability. However,the overuse of the grouting should be avoided due mainly to economic reasons,optimizing the project time and sometimes severe environmental issues.Insufficient grout spread can cause worse sealing results and decreasedurability. To control the process of grouting and predict the penetrationlength an analytical solution called Real Time Grouting Control theory (RTGC) hasbeen developed. This thesis aimed to evaluate RTGC theory on the equipmentrepresenting a one-dimensional model of a fracture called Varying Aperture LongSlot - VALS. The evaluation was based on a comparison between the calculated(predicted) penetration length according to RTGC theory and the realpenetration obtained in the experiments. Results of the tests show that the RTGCtheory is a good tool to predict the penetration length of the grout at thejoints with apertures close to the hydraulic apertures. At the apertures,significantly less than the hydraulic aperture, the results of the test andRTGC theory differ a lot.

<p>Grouting as a method of strengthening and sealing rock, soil and concrete is widely used. The possibilities of sealing structures are of great importance from both an economical and environmental point of view. The cost of grouting has in certain projects been as high as the cost for the blasting and excavation of the tunnel. To improve the technique of grouting with cement based material, it is necessary to focus on the properties of the used grout mixture. The ability of a grout to penetrate cavities, channels and porous material, the penetrability, depends on two things, the theology and the filtration tendency. Extensive laboratory tests on stable, low w/c-ratio, injection grouts show that the most significant limitation to their penetrability is the tendency of cement grains to agglomerate into an impermeable filter cake. The properties of a grout that may prevent passing obstructions in the flow path without the cement grains clogging and preventing further penetration is in this work called filtration tendency. An inert material mixture and a cement-based mixture are used for the investigations in this work. The inert material, which is crushed dolomite stone, does not react with the added water in the mixture. The used cement grouts are based upon three types of commercial available Portland cements and four Portland cements with modified grain size distribution curves. </p><p>Performed tests show that the grain size and grain size distribution is of great importance for the filtration tendency. According to performed experiments with inert and cement material, it seems to be advantageous for the penetrability to have a grain size distribution that contains neither too many fine or coarse grains. It is reasonable to believe that the grain size distribution should be relatively steep (narrow grain size range) between minimum and maximum grain size. The maximum grain size is of importance in terms of for example d_95. Too large maximum grain size will prevent penetration of the mixture through obstructions in the flow path. According to performed tests, the value of d₉₅, should be between </p><p>4-10 times smaller than the aperture to be penetrated by the cement based mixture. The small grain sizes are also of importance in order to achieve a low filtration tendency of the grout. This is because of the increased tendency for the small grains to flocculation into larger agglomerates, compared to larger grain sizes. </p><p>The filtration experiments with cement based grouts show that influences of parameters like surface chemistry (use of superplastisisers) and cement chemistry (hydration of cement grains) will strongly affect the filtration tendency of the mixture. </p><p>To visualize the phenomenon of filtration tendency it can be investigated on a larger scale than usually takes place. Filtration experiments in the scale of approximately 100:1 have been performed in order to see influences of grain concentration, grain shape and the penetrated slot aperture. It can be seen that used grain sizes (monodisperse and inert mixture) should be approximately at least 2-3 times smaller than the aperture to be penetrated by the mixture. Numerical experiments of filtration tendency have also been performed to investigate the possibilities to numerically simulate the influence of grain concentration and slot aperture. The numerical experiments are based on Eulerian flow modelling.</p>

<p>Rock groundwater has always caused major problems when tunnelling. Water leaking into tunnels can cause large problems, not only on the construction itself but also on the environment. A continuous water leakage can lead to a declining water supply, and geotechnical problems can occur as subsidence in the ground. Therefore it is of great importance to predict the consequences that can appear in the surroundings due to a declining groundwater surface.</p><p>The aim of the study was to investigate different methods for predicting leakage and changes in groundwater level due to tunnelling excavations in rock. This thesis was performed by comparing mathematical methods, actual groundwater changes and results from preliminary investigations.</p><p>Investigations were made for three railway tunnels planned by Botniabanan AB. Varvsbergstunneln (2 km), Åsbergstunneln (1 km) and Strannebergstunneln (1.4 km) all situated in the surroundings of Örnsköldsvik. During the time this thesis was performed, all tunnels have been fully excavated.</p><p>This thesis has emphasised difficulties in predicting groundwater behaviour as tunnelling excavations are made in rocks. The reason is the complex characteristics of rocks. The conductivity seems to be the parameter that is most difficult to determine with a high accuracy, and hence the accuracy shows in the results. Also the result is affected by the chosen mathematical method. Although careful preliminary investigations are made, it is hard to determine the rock characteristics with such accuracy that leakage and groundwater level changes can be predicted with high precision. However, mathematical methods are a good supplement when determining groundwater influences around railway tunnels in rock.</p> / <p>Vatten i berg har ofta inneburit stora problem vid tunnelbyggen. Vatten som läcker in i tunnlar kan orsaka stora problem på såväl konstruktionen som miljön och dessutom kan ett stort inflöde medföra stabilitetsproblem. Om vatten läcker in kontinuerligt kan omgivningarna dräneras så att vattentillgången minskar och geotekniska problem kan uppstå i form av sättningar i marken. Det är därför av stor vikt att prediktera inläckaget och de konsekvenser som kan uppstå på omgivningen till följd av en grundvattensänkning.</p><p>Syftet med arbetet har varit att undersöka olika metoder för att förutspå inläckage och nivåförändring av grundvatten i samband med tunnelbygge i berggrund. Arbetet utfördes genom att en jämförelse gjordes mellan matematiska metoder, verkliga grundvattenförändringar samt resultat från förundersökningar.</p><p>Undersökningar gjordes för tre järnvägstunnlar som är projekterade av Botniabanan AB. Varvsbergstunneln (2 km), Åsbergstunneln (1 km) samt Strannebergstunneln (1.4 km) som alla är belägna i närheten av Örnsköldsvik. Under examensarbetets gång har man hunnit driva igenom samtliga tre tunnlar.</p><p>Examensarbetet har påvisat svårigheterna i att förutspå grundvattnets beteende vid tunnelbyggen i berggrund. Detta beror på att berggrunden är ett komplext byggnadsmaterial vars egenskaper är svåra att bestämma. Konduktiviteten tycks vara den parameter som är svårast att bestämma med hög noggrannhet, och noggrannheten avspeglas i resultatet. Dessutom beror resultatet av vilken beräkningsmetod som väljs. Trots utförliga förundersökningar är det alltså svårt att bestämma bergets egenskaper med sådan noggrannhet att inläckage och nivåförändring av grundvatten kan förutspås med stor precision. Dock är matematiska metoder bra hjälpmedel för att bestämma grundvattenpåverkan kring järnvägstunnlar i berg.</p>

No presente trabalho são apresentadas sugestões de critérios executivos, fundamentados nos tratamentos efetuados em três obras brasileiras, em especial na Usina de Rasgão. O uso dos recursos da estatística também é proposto para avaliar a injeção de solo-cimento, ainda durante a fase executiva dos trabalhos. As análises realizadas mostram que as médias da pressão de iniciação da ruptura do maciço, em terreno natural, são crescentes com a profundidade. Observa-se também que à medida que o tratamento avança, os valores médios das pressões de ruptura e de injeção crescem nas linhas subseqüentes, tendendo a um valor constante com a profundidade e, conseqüentemente, indicando certa homogeneização do maciço. Destaca-se a performance do ensaio do tipo crosshole, executado ainda que em campo de prova, na avaliação da eficiência do tratamento. Nas paredes de uma trincheira escavada no campo de prova, observam-se fraturas hidráulicas predominantemente subverticais, algumas sub-horizontais e poucas inclinadas. Embora diferentes corantes tenham sido empregados nas caldas para observar as possíveis relações entre as fraturas hidráulicas, o processo de pigmentação adotado parece não ter sido adequado. / Soil-cement slurry grouting has been applied for a long time, although not is commonly used in Brazil, a tropical country where thick layers of soil are frequently found. The present paper is based on the soil mass treatment carried out at three different sites, particularly at Rasgão hydroelectric power plant. Statistics methods were applied in order to analyse the variation of the grouting pressures. They showed that pressure of fracturing were increasingly higher with depth in the natural soil mass. As long as the treatment goes on, it has also noticed that the average values of pressures fracturing and injection in each line of grouting became gradually higher, while the subsequent lines showed values of pressures tending to become constant with depth, suggesting a homogeneity of mechanical strength of the natural soil mass. Field geophysical tests performed before and after the grouting, using cross-hole technique, succeeded in verifying the efficiency of the treatment. The excavation of a trench into the test site indicated that the hydraulic fracturing has developed greatly in a vertical position, other than horizontally. Although different colours of pigments were mixed into the slurry in order to investigate the possible relationship among hydraulic fractures, that procedure proved to be unsuccessful.

No presente trabalho são apresentadas sugestões de critérios executivos, fundamentados nos tratamentos efetuados em três obras brasileiras, em especial na Usina de Rasgão. O uso dos recursos da estatística também é proposto para avaliar a injeção de solo-cimento, ainda durante a fase executiva dos trabalhos. As análises realizadas mostram que as médias da pressão de iniciação da ruptura do maciço, em terreno natural, são crescentes com a profundidade. Observa-se também que à medida que o tratamento avança, os valores médios das pressões de ruptura e de injeção crescem nas linhas subseqüentes, tendendo a um valor constante com a profundidade e, conseqüentemente, indicando certa homogeneização do maciço. Destaca-se a performance do ensaio do tipo crosshole, executado ainda que em campo de prova, na avaliação da eficiência do tratamento. Nas paredes de uma trincheira escavada no campo de prova, observam-se fraturas hidráulicas predominantemente subverticais, algumas sub-horizontais e poucas inclinadas. Embora diferentes corantes tenham sido empregados nas caldas para observar as possíveis relações entre as fraturas hidráulicas, o processo de pigmentação adotado parece não ter sido adequado. / Soil-cement slurry grouting has been applied for a long time, although not is commonly used in Brazil, a tropical country where thick layers of soil are frequently found. The present paper is based on the soil mass treatment carried out at three different sites, particularly at Rasgão hydroelectric power plant. Statistics methods were applied in order to analyse the variation of the grouting pressures. They showed that pressure of fracturing were increasingly higher with depth in the natural soil mass. As long as the treatment goes on, it has also noticed that the average values of pressures fracturing and injection in each line of grouting became gradually higher, while the subsequent lines showed values of pressures tending to become constant with depth, suggesting a homogeneity of mechanical strength of the natural soil mass. Field geophysical tests performed before and after the grouting, using cross-hole technique, succeeded in verifying the efficiency of the treatment. The excavation of a trench into the test site indicated that the hydraulic fracturing has developed greatly in a vertical position, other than horizontally. Although different colours of pigments were mixed into the slurry in order to investigate the possible relationship among hydraulic fractures, that procedure proved to be unsuccessful.

No description available.

Grouting as a method of strengthening and sealing rock, soil and concrete is widely used. The possibilities of sealing structures are of great importance from both an economical and environmental point of view. The cost of grouting has in certain projects been as high as the cost for the blasting and excavation of the tunnel. To improve the technique of grouting with cement based material, it is necessary to focus on the properties of the used grout mixture. The ability of a grout to penetrate cavities, channels and porous material, the penetrability, depends on two things, the theology and the filtration tendency. Extensive laboratory tests on stable, low w/c-ratio, injection grouts show that the most significant limitation to their penetrability is the tendency of cement grains to agglomerate into an impermeable filter cake. The properties of a grout that may prevent passing obstructions in the flow path without the cement grains clogging and preventing further penetration is in this work called filtration tendency. An inert material mixture and a cement-based mixture are used for the investigations in this work. The inert material, which is crushed dolomite stone, does not react with the added water in the mixture. The used cement grouts are based upon three types of commercial available Portland cements and four Portland cements with modified grain size distribution curves. Performed tests show that the grain size and grain size distribution is of great importance for the filtration tendency. According to performed experiments with inert and cement material, it seems to be advantageous for the penetrability to have a grain size distribution that contains neither too many fine or coarse grains. It is reasonable to believe that the grain size distribution should be relatively steep (narrow grain size range) between minimum and maximum grain size. The maximum grain size is of importance in terms of for example d95. Too large maximum grain size will prevent penetration of the mixture through obstructions in the flow path. According to performed tests, the value of d95, should be between 4-10 times smaller than the aperture to be penetrated by the cement based mixture. The small grain sizes are also of importance in order to achieve a low filtration tendency of the grout. This is because of the increased tendency for the small grains to flocculation into larger agglomerates, compared to larger grain sizes. The filtration experiments with cement based grouts show that influences of parameters like surface chemistry (use of superplastisisers) and cement chemistry (hydration of cement grains) will strongly affect the filtration tendency of the mixture. To visualize the phenomenon of filtration tendency it can be investigated on a larger scale than usually takes place. Filtration experiments in the scale of approximately 100:1 have been performed in order to see influences of grain concentration, grain shape and the penetrated slot aperture. It can be seen that used grain sizes (monodisperse and inert mixture) should be approximately at least 2-3 times smaller than the aperture to be penetrated by the mixture. Numerical experiments of filtration tendency have also been performed to investigate the possibilities to numerically simulate the influence of grain concentration and slot aperture. The numerical experiments are based on Eulerian flow modelling. / QC 20101007

The rheological properties of cement based grouts change with water/cement ratio and time, during the course of hydration. For this reason, it is desirable to be able to measure this change continuously, in-line, with a robust instrument during the entire grouting operation in the field. The rheological properties of commonly used cement grouts were determined using the Ultrasound Velocity Profiling combined with the Pressure Difference (UVP+PD) method. A non-model approach was used that directly provides the properties, and the results were compared with the properties obtained using the Bingham and Herschel-Bulkley rheological models. The results show that it is possible to determine the rheological properties, as well as variations with concentration and time, with this method. The UVP+PD method has been found to be an effective measuring device for velocity profile visualization, volumetric flow determination and the characteristics of the grout pump used. / <p>QS 2013</p>

No description available.