Abstract: A flexible wall device and method for measuring gas permeability coefficient and gas diffusion coefficient of unsaturated soil includes a gas washing device, a confining pressure-volume change system, a drying-wetting cycle control system and a gas measuring device. The drying-wetting cycle control system includes a humidity controller and valves. The gas measuring device includes a top lid, a cylindrical wall, a base, an upper chamber and a lower chamber. The top lid, the cylindrical wall and the base are connected by bolts and nuts, and the base has four passages, which are respectively connected to the gas washing device, the confining pressure-volume change system, the drying-wetting cycle control system and the gas measuring device, between the base and top lid are sequentially arranged from bottom to top as the lower chamber, lower perforated plate, lower permeable stone, sample, upper permeable stone, upper perforated plate, upper chamber, and control rod.

Abstract: The disclosure discloses a cone penetrometer for detecting multi-pollutants and the corresponding method based on laser induced fluorescence (LIF) and time domain reflectometry (TDR). The cone penetrometer includes two main modules: the TDR module mainly composes of a PEEK insulating rod, two gold-coated stainless steel probes and a coaxial cable; the LIF module mainly composes of endoscope image sensor, alumina glass lens, an ultraviolet LED with a 280 nm-wavelength, and an ultraviolet LED with a 325 nm-wavelength. Detection is performed to obtain the soil dielectric constant for characterizing the volumetric water content, electrical conductivity for the content of ionic pollutants, fluorescence intensity at 325 nm-wavelength for the content of polycyclic aromatic hydrocarbons, fluorescence intensity at 280 nm-wavelength for the content of humic acid, and soil images for soil types.

Abstract: A device and a method for in situ penetration measurement of gas transport parameters in an unsaturated soil layer. The device mainly consists of a gas supply system, a gas concentration display recorder, a gas pressure display recorder, a sleeve, a gas concentration sensor, a gas pressure sensor, a porous gas-permeable tube and a conical penetration head. The gas diffusion coefficient and permeability coefficient of the unsaturated soil can be obtained by only measuring the gas pressure value, the gas concentration value and the corresponding gas flow value of an unsaturated soil layer at a depth required to be tested, and substituting same into calculation formulae of the gas diffusion coefficient and permeability coefficient. The testing process of the method is simple and fast, and is low in cost, simple in operation and convenient in calculation.

Abstract: A data processing method for an analogue modelling experiment of a hypergravity geological structure includes steps of: performing two-dimensional photographing and three-dimensional elevation scanning with an analogue modelling experiment device with a curved model surface for the hypergravity geological structure, so as to collect initial elevation data and initial velocity field data; and correcting the initial elevation data and the initial velocity field data to obtain corrected elevation data and corrected velocity field data. The data processing method can realize orthographic correction and three-dimensional projection transformation of initial elevation data, as well as orthographic correction and two-dimensional projection transformation of initial velocity field data, which can more realistically and objectively reflect the experimental phenomenon, which is conducive to truly expressing the experimental results and facilitates the analogy analysis with the actual geological prototype.

Abstract: A device for an analogue modeling experiment of a geological structure under a hypergravity field of a large-scale centrifuge is provided. A bottom plate is placed on a basket of the centrifuge and mounted with screw rod components; screw rods are arranged in parallel with the bottom plate; diverters, screw rod supporting columns, sliding guide rails and a motor are arranged on the bottom plate; output shafts at two ends of the motor are respectively connected to the two diverters; the diverters are connected with one end of the corresponding screw rod; a fixed baffle plate is connected with the screw rods and is embedded with the sliding guide rails; a detachable baffle plate is arranged at a lower part of the fixed baffle plate and has a lower part connected with a swing baffle plate through a hinge; and a curved table is arranged on the bottom plate.

Abstract: A device and a method for in situ penetration measurement of gas transport parameters in an unsaturated soil layer. The device mainly consists of a gas supply system, a gas concentration display recorder, a gas pressure display recorder, a sleeve, a gas concentration sensor, a gas pressure sensor, a porous gas-permeable tube and a conical penetration head. The gas diffusion coefficient and permeability coefficient of the unsaturated soil can be obtained by only measuring the gas pressure value, the gas concentration value and the corresponding gas flow value of an unsaturated soil layer at a depth required to be tested, and substituting same into calculation formulae of the gas diffusion coefficient and permeability coefficient. The testing process of the method is simple and fast, and is low in cost, simple in operation and convenient in calculation.

Abstract: The present disclosure provides a supergravity simulation system for in-situ stress field and seepage field for deep earth engineering, comprising: a triaxial pressure chamber for placing a model and providing in-situ axial pressure, confining pressure and seepage field of deep earth structure; a simulation control device for providing pressure liquid and pore water to the triaxial pressure chamber to generate the aforementioned axial pressure, confining pressure and seepage field, and controlling the values of the axial pressure, confining pressure and seepage field; a signal acquisition device for monitoring the deformation and seepage process of the model during the test. The invention improves the similarity, reliability, and accuracy of the simulation test, and it can output pressure with an accuracy of 1% or constitute the pore water pressure difference with an accuracy of 1% to the triaxial pressure chamber through the command of the control unit.

Abstract: The present disclosure provides a supergravity simulation system for in-situ stress field and seepage field for deep earth engineering, comprising: a triaxial pressure chamber for placing a model and providing in-situ axial pressure, confining pressure and seepage field of deep earth structure; a simulation control device for providing pressure liquid and pore water to the triaxial pressure chamber to generate the aforementioned axial pressure, confining pressure and seepage field, and controlling the values of the axial pressure, confining pressure and seepage field; a signal acquisition device for monitoring the deformation and seepage process of the model during the test. The invention improves the similarity, reliability, and accuracy of the simulation test, and it can output pressure with an accuracy of 1% or constitute the pore water pressure difference with an accuracy of 1% to the triaxial pressure chamber through the command of the control unit.

Abstract: A data processing method for an analogue modelling experiment of a hypergravity geological structure includes steps of: performing two-dimensional photographing and three-dimensional elevation scanning with an analogue modelling experiment device with a curved model surface for the hypergravity geological structure, so as to collect initial elevation data and initial velocity field data; and correcting the initial elevation data and the initial velocity field data to obtain corrected elevation data and corrected velocity field data. The data processing method can realize orthographic correction and three-dimensional projection transformation of initial elevation data, as well as orthographic correction and two-dimensional projection transformation of initial velocity field data, which can more realistically and objectively reflect the experimental phenomenon, which is conducive to truly expressing the experimental results and facilitates the analogy analysis with the actual geological prototype.

Abstract: A device for an analogue modeling experiment of a geological structure under a hypergravity field of a large-scale centrifuge is provided.