A 3D Fracture Network Model for the Undisturbed Rock Mass at the Songta Dam Site Based on Small Samples

2015 ◽  
Vol 49 (2) ◽  
pp. 611-619 ◽  
Author(s):  
Xudong Han ◽  
Jianping Chen ◽  
Qing Wang ◽  
Yanyan Li ◽  
Wen Zhang ◽  
...  
Keyword(s):  
Rock Mass ◽  
Network Model ◽  
Fracture Network ◽  
Small Samples ◽  
Undisturbed Rock ◽  
Dam Site ◽  
3D Fracture Network

scholarly journals Grouting Process Simulation Based on 3D Fracture Network Considering Fluid–Structure Interaction

2019 ◽  
Vol 9 (4) ◽  
pp. 667 ◽  
Author(s):  
Yushan Zhu ◽  
Xiaoling Wang ◽  
Shaohui Deng ◽  
Wenlong Chen ◽  
Zuzhi Shi ◽  
...  
Keyword(s):  
Rock Mass ◽  
Network Model ◽  
Process Simulation ◽  
Fractured Rock ◽  
Fluid Structure Interaction ◽  
Fracture Network ◽  
Fractured Rock Mass ◽  
Fluid Structure ◽  
Structure Interaction ◽  
3D Fracture Network

Grouting has always been the main engineering measure of ground improvement and foundation remediation of hydraulic structures. Due to complex geological conditions and the interactions between the grout and the fractured rock mass, which poses a serious challenge to the grouting diffusion mechanism analysis, fracture grouting has been a research hotspot for a long time. In order to throw light on the grout diffusion process in the fractured rock mass and the influence of grout on the fracture network, and to achieve more realistic grouting numerical simulation, in this paper a grouting process simulation approach considering fluid–structure interaction is developed based on the 3D fractured network model. Firstly, the relationship between fracture apertures and trace lengths is used to obtain a more realistic value of fracture aperture; then a more reliable model is established; subsequently, based on the 3D fracture network model, different numerical models are established to calculate fluid dynamics (grout) and structure deformation (fractured rock mass), and the results are exchanged at the fluid–structure interface to realize the grouting process simulation using two-way fluid-structure interaction method. Finally, the approach is applied to analyze the grouting performance of a hydropower station X, and the results show that the grouting simulation considering fluid–structure interaction are more realistic and can simultaneously reveal the diffusion of grout and the deformation of fracture, which indicates that it is necessary to consider the effect of fluid–structure interaction in grouting simulation. The results can provide more valuable information for grouting construction.

Construction of 3D Discrete Fracture Network Model using Structural and Hydrogeological Data

2020 ◽  
Author(s):  
Mohammadreza Jalali ◽  
Zhen Fang ◽  
Pooya Hamdi
Keyword(s):  
Rock Mass ◽  
Network Model ◽  
Fracture Network ◽  
Crystalline Rock ◽  
Discrete Fracture Network ◽  
Seismic Survey ◽  
Discrete Fracture ◽  
Dfn Model ◽  
Hydrogeological Data

<p>The presence of fractures and discontinuities in the intact rock affects the hydraulic, thermal, chemical and mechanical behavior of the underground structures. Various techniques have been developed to provide information on the spatial distribution of these complex features. LIDAR, for instance, could provide a 2D fracture network model of the outcrop, Geophysical borehole logs such as OPTV and ATV can be used to investigate 1D geometrical data (i.e. dip and dip direction, aperture) of the intersected fractures, and seismic survey can mainly offer a large structure distribution of the deep structures. The ability to combine all the existing data collected from various resources and different scales to construct a 3D discrete fracture network (DFN) model of the rock mass allows to adequately represent the physical behavior of the interested subsurface structure.</p><p>In this study, an effort on the construction of such a 3D DFN model is carried out via combination of various structural and hydrogeological data collected in fractured crystalline rock. During the pre-characterization phase of the In-situ Stimulation and Circulation (ISC) experiment [Amann et al., 2018] at the Grimsel Test Site (GTS) in central Switzerland, a comprehensive characterization campaign was carried out to better understand the hydromechanical characteristics of the existing structures. The collected multiscale and multidisciplinary data such as OPTV, ATV, hydraulic packer testing and solute tracer tests [Jalali et al., 2018; Krietsch et al., 2018] are combined, analyzed and interpreted to form a combined stochastic and deterministic DFN model using the FracMan software [Golder Associates, 2017]. For further validation of the model, the results from in-situ hydraulic tests are used to compare the simulated and measured hydraulic responses, allowing to evaluate whether the simulated model could reasonably represent the characteristics of the fracture network in the ISC experiment.</p><p> </p><p><strong>References</strong></p><ul><li>Amann, F., Gischig, V., Evans, K., Doetsch, J., Jalali, M., Valley, B., Krietsch, H., Dutler, N., Villiger, L., Brixel, B., Klepikova, M., Kittilä, A., Madonna, C., Wiemer, S., Saar, M.O., Loew, S., Driesner, T., Maurer, H., Giardini, D., 2018. The seismo-hydromechanical behavior during deep geothermal reservoir stimulations: open questions tackled in a decameter-scale in situ stimulation experiment. Solid Earth 9, 115–137.</li> <li>Golder Associates, 2017. FracMan User Documentation.  Golder Associates Inc, Redmond WA.</li> <li>Krietsch, H., Doetsch, J., Dutler, N., Jalali, M., Gischig, V., Loew, S., Amann, F., 2018. Comprehensive geological dataset describing a crystalline rock mass for hydraulic stimulation experiments. Scientific Data 5, 180269.</li> <li>Jalali, M., Klepikova, M., Doetsch, J., Krietsch, H., Brixel, B., Dutler, N., Gischig, V., Amann, F., 2018. A Multi-Scale Approach to Identify and Characterize the Preferential Flow Paths of a Fractured Crystalline Rock. Presented at the 2<sup>nd</sup> International Discrete Fracture Network Engineering Conference, American Rock Mechanics Association.</li> </ul>

Probability Statistical Model and Network Simulation Technology of Random Fractured Rock Mass

2014 ◽  
Vol 580-583 ◽  
pp. 679-683
Author(s):  
Chun Xiu Han ◽  
Dong Hua Zhou ◽  
Wen Yuan Liao ◽  
Xu Chen ◽  
Long Qi Li ◽  
...  
Keyword(s):  
Monte Carlo Simulation ◽  
Rock Mass ◽  
Network Model ◽  
Fractured Rock ◽  
Fracture Network ◽  
Field Investigation ◽  
Fractured Rock Mass ◽  
Monte Carlo Simulation Technique ◽  
Geometrical Characteristics ◽  
Statistical Sense

Based on field investigation of random fractured rock mass, the sample parameters are put to statistical analysis, and 2-D fracture network model is established with probability-statistics theory and Monte-Carlo simulation technique. Finally, 2-D fracture network model is formed, which gain fracture distributed regularity in statistical sense, and is of important meaning to describe the fracture geometrical characteristics.

Variational Inequality Formulation Method for Unconfined Seepage in 3D Fracture Network

2013 ◽  
Vol 405-408 ◽  
pp. 2084-2088
Author(s):  
Wei Sheng Xu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Free Surface ◽  
Rock Mass ◽  
Variational Inequality ◽  
Numerical Stability ◽  
Fracture Network ◽  
The Finite Element Method ◽  
3 Dimensional ◽  
3D Fracture Network

A variational inequality formulation method to define the free surface of fracture network was given, related formulas were deduced and the Finite Element Method was used to solve the equations. By computing, the following conclusions were gotten, that is the variational inequality formulation method to solve unconfined seepage in 3 dimensional fracture network of rock mass is possible, and had a better numerical stability and much less mesh-depenciency.

Study on Three-Dimensional Fracture Persistence of a Jointed Rock Mass in a Dam Site in China

2012 ◽  
Vol 594-597 ◽  
pp. 574-580 ◽  
Author(s):  
Xiao Ming Wang ◽  
Lu Xia ◽  
Qing Chun Yu
Keyword(s):  
Rock Mass ◽  
Scale Effect ◽  
Three Dimensional ◽  
Fracture Network ◽  
Jointed Rock ◽  
Mean Value ◽  
Three Dimension ◽  
Projection Plane ◽  
Dam Site ◽  
Dip Angle

Fracture persistence is an essential parameter to evaluate the stability of rock mass. In the present paper，a projection method based on fracture network modeling was employed to study the three-dimension(3D) fracture persistence of abutment rock mass in Wudongde dam site. Fracture data from an exploration tunnel was used to generate a fracture network model. Subsequently in the fracture network, numbers of projection planes with different positions and different attitudes were set. A computer program was written to calculate 3D fracture persistence. The scale effect on persistence is discussed. The distribution characteristic of persistence values was analyzed. Also the change of lateral persistence with directions was studied. The following conclusions were drawn from the study：(1)The horizontal persistence values do not have a noticeable scale effect, while the effect of size on the lateral persistence is significant;(2)The lateral persistence values conform to a normal distribution with a mean value of 3.9;(3)The persistence value varies with the direction of projection plane. The steep dip angle corresponds to a low persistence value. A maximum value is obtained when the trend and dip angle of the projection plane are 175°and 65°.

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