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In the large hydraulic concrete structure that conventional nondestructive testing technique can’t implement quantitative detection, using steady Rayleigh wave technique can acquire various characteristic parameters of concrete. The paper introduces the principle and detection system of steady Rayleigh wave technique systematically, and makes detection experiments to introduce steady Rayleigh wave e technique and application progress of it in quality of large hydraulic concrete and nondestructive detection of crack depth. The practice proves that steady Rayleigh wave detection technique has the characteristics of strong antijamming capability and higher detection precision.

Due to the interference of noise, filtering technology is applied to achieve gravity anomaly for airborne gravimetry. Kalman filtering and smoothing are discussed and implemented for data processing of airborne gravimetry in this paper. Firstly, the algorithms of Kalman filtering and smoothing are introduced. Then, the system model for solving the gravity anomaly is established which is based on the dynamic equation and the hardware design equations. Finally, the result of Kalman filtering and smoothing would be compared with digital FIR low pass filter, and it is proved that Kalman filter and smoother could obtain more accurate result than FIR low pass filter as that the solving error of Kalman filter and smoother is improved within 1 mGal compared with the theory standard obtained by GT-1A software.

The chambers of certain coal mine in Shandong such as central substation situate in soft rock which consists of mudstone and fine sandstone, etc. Obvious ground pressure behaviors, large deformation and failure of surrounding rock have serious effect on mine safety production, with the impact of various complicated deep large ground pressure. This paper presents a rational scheme to control the surrounding rock steadily, based on analysis of deformation and failure on large section soft rock chamber, combined with the concept of the" combined supporting technology of long and short anchors" and "the combined supporting technology of three anchors".

Once the lead abutment pressure influence the fault structure, its internal rock mass is damaged easily while the fault structures are the most vulnerable of mining influence weak link. If the fault structures conduct the aquifer, the mine water inrush will occur. This paper researchs water level of Taiyuan limestone aquifer with three-dimensional form simulation and analyzes mine water movement characteristics and the change of water level and hydraulic contact of each aquifer combining with complex geological conditions of Wugou mine, aiming at tectonic evolution and tectonic combination characteristic of the mine, according to the long observation hole material. Combining with water pressure test results and drilling and geophysical prospecting achievement, using daubing coefficient method to analyze sealing of fault structure, we conclude that faults are pressure-torsional normal faults which their fault zone is compact and has high strength so we can narrow even do not leave set fault waterproof pillar in Wugou mine.

The paper has analyzed the mechanical mechanism of movement and deformation of overlying strata and surface on stope, defined the moving structures of the overlying strata of three strata space forms, explored the mechanism of surface subsidence caused by loose layers’ pressure consolidation , and pointed out that when the loose layers are much thicker, what is indispensable is that, the pressure consolidation of loose layers loosed water, or soil body’s deformation leading to additional stress in the mining soil body, and the dissipation of excess pore water pressure resulting in the consolidation. And according to the surface subsiding features of thick loose layers in mining area, the paper has applied the correction model by probability integral method to predict subsidence with a rather satisfying prediction result.

Brazing diamond grits to steel substrate using Ni-based filler alloy was carried out via laser in an argon atmosphere. Thermodynamic analysis was performed in order to research the interfacial reaction mechanism of diamond and Ni-Cr alloy during high temperature brazing. Meanwhile, microstructure of the interfacial layer was experimentally detected by scanning electron microscope (SEM), energy dispersion spectrometer (EDS) and X-ray diffraction (XRD) in this paper. The results indicate that according to the thermodynamic theory the interfacial reaction has been proved feasible, and during brazing high strength bonding between diamond grits and the steel substrate has been successfully realized because the chromium in the Ni-based alloy segregated preferentially to the surface of the diamond to form a chromium-rich reaction product Cr3C2, and the bond between the alloy and the Diamond was established through the reaction product.