The subject invention pertains to a suction-controllable triaxial test system and a method for studying the micro-hydro-mechanical behavior of unsaturated soils through the visualization of the in-situ evolution of three-dimensional (3D) microstructure upon triaxial loading in a ((p-u.sub.a), q, s) space. The triaxial apparatus can be small enough to be operated within a micro-focus or nano-focus X-ray CT scanner. Internal characteristics and 3D movements of soil particles and the water and air in soil pores can be visualized during in-situ controllable hydro-mechanical loading processes without disturbing the soil sample. The evolution of 3D micro-structure of unsaturated soil samples of varying matric suction can be directly related with their element-scale behavior for conducting cross-scale fundamental studies.

The subject invention pertains to a suction-controllable triaxial test system and a method for studying the micro-hydro-mechanical behavior of unsaturated soils through the visualization of the in-situ evolution of three-dimensional (3D) microstructure upon triaxial loading in a ((p-u.sub.a), q, s) space. The triaxial apparatus can be small enough to be operated within a micro-focus or nano-focus X-ray CT scanner. Internal characteristics and 3D movements of soil particles and the water and air in soil pores can be visualized during in-situ controllable hydro-mechanical loading processes without disturbing the soil sample. The evolution of 3D micro-structure of unsaturated soil samples of varying matric suction can be directly related with their element-scale behavior for conducting cross-scale fundamental studies.

A directional drilling-exploring-monitoring integrated method for guaranteeing safety of an underwater shield tunnel includes: drilling a small-diameter borehole below a water area, and establishing an initial geological model; reaming the small-diameter borehole into a large-diameter borehole, placing a parallel electrical method (PEM) power cable and a monitoring optical fiber cable into the large-diameter borehole, acquiring zero field data, primary field data and secondary field data through carbon rod measurement electrodes before tunnel excavation, and processing the data with an existing inversion method to form an inversion image, thereby obtaining a refined geological model of a stratum; starting the tunnel excavation, and respectively acquiring a disturbance condition of rock and soil and a sedimentation and deformation condition of rock and soil around the tunnel during the excavation, thereby implementing safety excavation of the tunnel; and continuously monitoring the tunnel and the surrounding rock and soil in later use of the tunnel.

A directional drilling-exploring-monitoring integrated method for guaranteeing safety of an underwater shield tunnel includes: drilling a small-diameter borehole below a water area, and establishing an initial geological model; reaming the small-diameter borehole into a large-diameter borehole, placing a parallel electrical method (PEM) power cable and a monitoring optical fiber cable into the large-diameter borehole, acquiring zero field data, primary field data and secondary field data through carbon rod measurement electrodes before tunnel excavation, and processing the data with an existing inversion method to form an inversion image, thereby obtaining a refined geological model of a stratum; starting the tunnel excavation, and respectively acquiring a disturbance condition of rock and soil and a sedimentation and deformation condition of rock and soil around the tunnel during the excavation, thereby implementing safety excavation of the tunnel; and continuously monitoring the tunnel and the surrounding rock and soil in later use of the tunnel.

A hierarchical early-warning system for landslide probability issues a first level warning based on measured rainfall amounts exceeding a determined threshold, a second level warning, after the first level warning, based additionally on measured soil moisture content measured at different levels, and Factor of safety derived from forecasted pore pressure (FPP) each exceeding a determined threshold, a third level warning, after the first and the second level warnings, based additionally on ground movement measurements compared to a determined threshold, and a fourth level warning after the first, second and third level warnings, based additionally on data from movement-based sensors including strain gauge data.

Methods and systems for determining fracture and matrix permeability of a subsurface formation. The system includes two upstream reservoirs and two downstream reservoirs, and a sample cell connecting to the reservoirs with valves. The sample cell has a confining pressure (CF) from a fluid. A horizontal plug sample with sleeve is placed in a measurement cell with the confining fluid (CF). A pressure gauge is connected to the small upstream reservoir, and a pressure gauge is connected to the small downstream reservoir. The results provide two sets of effective-stress-dependent permeability values (including fracture permeability and matrix permeability, respectively) for characterizing the reservoir properties.

Methods and systems for determining fracture and matrix permeability of a subsurface formation. The system includes two upstream reservoirs and two downstream reservoirs, and a sample cell connecting to the reservoirs with valves. The sample cell has a confining pressure (CF) from a fluid. A horizontal plug sample with sleeve is placed in a measurement cell with the confining fluid (CF). A pressure gauge is connected to the small upstream reservoir, and a pressure gauge is connected to the small downstream reservoir. The results provide two sets of effective-stress-dependent permeability values (including fracture permeability and matrix permeability, respectively) for characterizing the reservoir properties.

A downhole tool may comprise a mandrel, wherein the mandrel is a structural support for the downhole tool; one or more arms, wherein the one or more arms are attached to the mandrel; and a pad, wherein the pad is connected to the one or more arms. The pad may comprise a material, where the material expands or contracts from an external electromagnetic field; an insulator, wherein the insulator is connected at a first end to the material; and an electrode, wherein the electrode is connected to the insulator. A method may comprise applying a time varying biasing voltage to a material, wherein the material exhibits mechanical strain; taking a first measurement and a second measurement with at least one operating frequency with an electrode; calculating a mud property based at least in part on the first measurement and the second measurement; and applying a mud effect removal algorithm to the mud property.

A method for characterizing complexity of rock fracture based on fractal dimension and a device thereof are provided. The method includes steps of: collecting rock fracture samples of a rock, and collecting basic parameters of the rock; determining a fractal dimension of a rock fracture morphology of the rock; calculating the fractal dimension of the rock; calculating a complexity coefficient Fc of rock fracture of the rock; and characterizing a complexity of rock fracture of the rock based on the complexity coefficient Fc of rock fracture of the rock. In the present invention, combined with the fractal geometry theory, fracture complexity coefficient of shale rocks is redefined and calculated to accurately characterize rock fracture morphology, so that characteristics of rock fracture morphology is correctly understood and affecting factors of fracture morphology is analyzed.

A method for characterizing complexity of rock fracture based on fractal dimension and a device thereof are provided. The method includes steps of: collecting rock fracture samples of a rock, and collecting basic parameters of the rock; determining a fractal dimension of a rock fracture morphology of the rock; calculating the fractal dimension of the rock; calculating a complexity coefficient Fc of rock fracture of the rock; and characterizing a complexity of rock fracture of the rock based on the complexity coefficient Fc of rock fracture of the rock. In the present invention, combined with the fractal geometry theory, fracture complexity coefficient of shale rocks is redefined and calculated to accurately characterize rock fracture morphology, so that characteristics of rock fracture morphology is correctly understood and affecting factors of fracture morphology is analyzed.