Various methods provided for reducing the seepage of water from the dam foundation and abutments that the most common techniques is Curtain Grouting. Quality and efficiency of Grouting operation depend on various factors such as absorption, grout properties and Grouting pressure. One of the most effective parameter is the Grouting pressure, because of overpressure, causing hydraulic fracturing inrock mass and low Grouting pressure, causing partial stay of the operation and the site is not completely sealed. So far, different comments, equations, tables and charts have been provided to calculate the necessary pressure in Grouting operation. In this paper, has been investigate the effect of Grouting pressure in difference stag of Seymareh dam. For this purpose, the Grouting pressure is Calculated based on the analytical equations and compared with the actual pressures and finaly the best Model is selected. The results show that Groundy and Zaruba equations (with horizontal joints) prepare more accurate estimates of the Grouting pressure than others. Also, new Equation is developed to calculate of Grouting pressure as a function of Lug eon number that is able to calculate the acceptable grout pressure.

Cement grout is grouted in rock joints of the foundations of dams to prevent water leakage and strengthen the foundation. One of the techniques used to control the Grouting operation is the Grouting intensity number (GIN), which is equal to the sum of the Grouting pressure and volume and represents the Grouting energy. pressure in the rock joints creates a hydraulic lifting force that should not exceed its allowable limit so as not to lead hydraulic jacking and failure. The maximum pressure and Grouting intensity number are determined accordingly. Simplifying the plan of the grouted joint, which is modeled as a thin cylinder with a radius of the Grouting extension radius, the present study determines the relationship between hydraulic lifting force with Grouting pressure and Grouting intensity number. In this regard, the joint aperture coefficient was defined and determined based on the rock permeability (the amount of joint aperture). Then, following the geometry of rock-soil mass at the top of the joint, which is considered as a truncated cone with a β angle, for the first time approximate and exact mathematical equations were obtained to determine the permissible hydraulic lifting force (based on the approximate and exact formulas of truncated cone volume). Besides, its approximate and exact mathematical equations were compared. Then, following the principle that the hydraulic lifting force should not exceed the allowable limit, the maximum pressure and Grouting intensity number were determined. Finally, by defining two parameters the normal pressure and the normal spreading length, the maximum normal pressure was set so that the hydraulic lifting force to be within the allowable range and prevent hydraulic jacking and failure

Tunnel Boring Machine (TBM) is used widely to bore long tunnels in hard rocks. If you choose shield TBMs, precast concrete segments should be installed as permanent tunnel lining. This lining is inherently distinct and therefore in analytical and numerical analyses, the continuity assumption is not acceptable for simplifying. The segmental linings show certain behavior under various loads applied by rock, machine and tunneling processes (such as Grouting). In this study, the behavior of segmental lining of Sabzkouh water conveyance tunnel has been compared to full (continuous) lining. In this paper, the behavior of tunnel segmental lining by assigning normal and shear stiffness values for longitudinal and circumferential joints of segments is compared with the continuous lining. The effect of the Grouting pressure between rock and segments on the behavior of the tunnel segment is analyzed. Under uniform Grouting load, the results of numerical modeling executed by finite difference method show maximum internal forces occur in the joints of segments. With increasing Grouting pressure, axial force and bending moment in the joints of the segments is reduced. Moreover, the Grouting pressure increases displacements in the segmental lining. In practice, this increase sometimes causes cracking or stepping between segments.

Controlling of any leakage in dams is a basic requirement for their safe design. For this purpose, doing of investigation on geological structures of the dam site is necessary for design of any impermeable systems. After the watering of the Zavin dam, in north east of Iran, leakage was observed from the left abutment when the water level was increased. An extensive study was performed to find out the reason of the leakage as well as proposing a mitigation measure. This study included an extensive field geological survey in dam site. Moreover based on the geological and the geotechnical information and a seepage analysis the design of the initial impermeable grout curtain was modified. A new method of Grouting with balanced Grouting pressure and water head was designed and utilized in improvement of the existing grout curtain while the water level in reservoir was considerably high. This execution method is called as "Grouting with balanced pressure" here. The method was successfully used in the case of the Zavin dam. During the Grouting operation, the grout suspension was regularly tested to avoid any segregation. This was important for satisfactory filling of the joints and discontinuities of the rock mass of the abutment. The operation resulted in complete control of the seepage in downstream side.

One of the essential parameters in Grouting operations for various purposes of foundation improvement is the optimal Grouting pressure for the penetration of cement slurry. In this study, the role of effective parameters in determining the optimal Grouting pressure was investigated based on Grouting data and engineering geology data obtained in drilling and Grouting workshops from 42 dam projects in Iran and the world. Then, Multiple Linear Regression (MLR) and Multiple Nonlinear Regression (MNLR) methods and soft computation methods such as Fuzzy System (FUZZY), Artificial Neural Network (ANN), and Adaptive Neuro-Fuzzy Inference System (ANFIS) were used to estimate optimal Grouting pressure from these parameters. The results show that the depth (D), geological strength index (GSI), and uniaxial compressive strength of rock mass (UCSRM) have the highest correlation in the Grouting pressure (GP), respectively. Among the statistical methods, the ANFIS method with a coefficient of determination (R2 = 0.803) and the root mean square error (RMSE = 4.47) performs better than other models.Additionally, the results show that R2 and RMSE are improved in FUZZY, ANN, and ANFIS analysis methods compared to MLR and MNLR. In the fuzzy system, fuzzy rules are formulated using the worker's experience as well as the results of studies of others. These rules select the output using specific ranges of input values, so fuzzy systems models show more flexibility and give better results than the data used in the model.

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 .

There are several outstanding factors engaged in the cement grouts filtration. These factors can be evaluated from some aspects including the characteristics of the grout, cement and Grouting materials, Grouting environment, interaction between the grout and environment and Grouting pressure among which fewer studies have been performed on the role of the Grouting pressure in the grout filtration. In this research practical results of cement Grouting have been reviewed in two dam projects as examples. The results depict that the increase in the Grouting pressure considerably affects the rate of cement take and penetration. In practice, the cement penetration rate into the rock is higher when the Grouting pressure is variable. This is vice versa under constant Grouting pressure. In other words, the increasing steps of Grouting pressure may erode the grout cake at each stage. This leads to optimal penetration of the grout and decreases the watertightening costs of the dam foundation, tunnels and structures requiring cement Grouting.

Grouting proceedings are one of the ways to decrease permeability and to increase the resistance and fixation of jointed rocks in construction area. One of the following issues in this operation is to estimate the penetrating radius and the amount of cement grout that has been introduced as the main parameters of Grouting operation. The analytical and numerical methods have been used to estimate these parameters. In analytical method 5 models were presented. In numerical modeling the profile of rock block, bore and grouted cleft were designed by UDEC software and then grout features and final pressure of Grouting were entered. To investigate the above models, as a case study, the geotechnical data and Grouting information of Seymareh site dam were used.The results of numerical and analytical modeling were compared with the real corrode (recorded in site) and analyzed. The computations show that in analytical modeling, the first model (Janson) can provide a better and more suitable assessment from the amount of injected grout in comparison with other models. The results of numerical modeling have acceptable accordance with the results of analytical models. But totally, numerical modeling can provide better assessment in the amount of injected grout. However, numerical computations are time taking and not easy to do in field because of the lack of calculating facilities during the operation, so, the use of analytical models, due to some simplifications, seems to be more practical during the Grouting operation.

In this paper, the improvement potential of calcareous sand produced in Kish Island by using a chemical grout is investigated.The main characteristics of this sand are its high voids ratio and tendency to be crushed under moderate stresses. The improvement process of sand is conducted using a sodium silicate grout injected with additives such as formamide and sodium aluminate. Samples were prepared in different initial relative densities and then grouted. It is observed that the maximum uniaxial strength, initial tangent modulus and failure strain are obtained in water/silicate ratio of 0.5. Uniaxial strength and initial tangent modulus are increased with time but failure strain variation with time is a function of water/sodium silicate ratio and additives content. Formamide increases and sodium aluminate decreases the uniaxial strength and initial tangent modulus. Furthermore, increasing of grain size decreases grouted sand uniaxial strength. Uniform grading results in brittle and non-uniform grading results in ductile stress-strain behavior. Presence of sulphates and chlorides solved in water reduces the uniaxial strength and increases the initial tangent modulus of grouted sand.