Showing 3 results for Grouting
Volume 3, Issue 1 (11-2009)
Abstract
(Paper pages 523-542) This paper presents a rigid circular footing model with specified properties and dimensions on a sandy-clay soil with Mohr-Coulomb material. This model is analyzed dynamically with finite difference 2D FLAC software under vertical component of ground excitations. Then the soil is improved with cement grouting and analyzed again. Consequently, the load-settlement curves under a circular footing, due to vertical component of ground accelerations through the underlying soil, are plotted. Also the dynamic bearing capacity of natural and soil cemented foundation is presented and discussed. The analysis results show that adding 2, 4 and 6 percent of cement, with certain conditions, cause 2.7, 4.2 and 7.0 times increase in dynamic bearing capacity, respectively, in comparison to normal soil.
Volume 3, Issue 2 (4-2010)
Abstract
(Paper pages 757-772) Jet grouting is a method for improving of soil properties and its physical characteristics. However, in this method due to high pressure and velocity of cement slurry the soil structure has been damaged as some parts are moved from the borehole replacing with cement slurry. The grains, which are remained in the borehole, mixed with slurry (cement) and create an improved mass of soil. This mass is named “Soilcrete”. Soilcrete mass has special characteristics such as high strength, low deformability and very low permeability. In this paper, principles governing to jet grouting and effective parameters have been explained. Then the test results obtained from Soilcrete column have been analyzed and discussed. Based on the results, jet grouting has led to increase and improvement of physical and mechanical characteristics of soils, i.e. uniaxial compressive strength, cohesion and internal friction angle. Finally the values of jet grouting parameters are recommended in order to achieve larger diameters in the mentioned site based on trial grouting results
A Zolfaghari, A Sohrabi Bidar, Mr Malekijavan, M Haftani,
Volume 8, Issue 2 (11-2014)
Abstract
Today the effects of grouting are usually confirmed by the results of permeability tests but this method is not enough to show the changes in mechanical properties of rock masses. Although many investigators use the in situ tests for evaluation of rock mass mechanical property improvement. But this tests are time consuming and expensive. Grouting reduces the permeability and improves the condition of joints and ultimately increases the rate of rock mass classification in rock engineering. So with measurement of rock mass quality index values (Q-value) in cores obtained from grouted boreholes, the efficiency and success in improving the mechanical properties of rock mass can be showed. This paper for first time introduces Q-logging as a simple method to assess the impact of grouting in improvement of the rock mass quality. Here in, the results of Q-Logging in trial injection panels in the Bakhtiary, Bazoft and Khersan II dams have been examined. The deformation modulus were calculated from the Q-Logging for before and after of grouting. Results show that there is a good agreement between calculated rock mass parameters based on the Q-Logging method and the measured from in-situ test in the studied site. This agreement confirms the efficiency and applicability of the Q- Logging method for assessment of grouting success as well as the estimation of the rock mass parameters in grouted areas. Also it has been shown that the deformation modulus in weak rock mass with low quality has been more improved than rock mass with beater quality.
