In deep roadway mining, high water pressure causes rock mass cracking and weakens the overall strength, affecting the stability of underground metal mine mining roadways. Therefore, using a numerical simulation method, we analyzed the strain softening characteristics of rocks after the inflexion point of elasticity and studied the strain distribution and the minimum support resistance under high-pressure groundwater conditions. Considering the groundwater pressure and effective porosity on the strain softening characteristics of the surrounding rocks, we investigated the critical groundwater pressure under which the surrounding rocks would remain stable. Actual engineering verification helps to obtain the supporting characteristic curves under different influencing factors. We found that water pressure and effective porosity are the significant factors that decide the development scope of the plastic zone. The more significant the increase of the plastic zone, the more notable the changes in the support curve. Moreover, the plastic zone is likely to occur when the hydraulic head is between 30 and 50 m; when the hydraulic head exceeds 50 m, it is likely to produce a relaxation zone.

The low-field NMR method is introduced to explore the effect of various experimental conditions on hydration number during hydrate dissociation in methane hydrate-bearing sediments. It is shown that the NMR signal peak value of water is independent of the dry density of sediment, gas pressure, and salt concentration and significantly influenced by temperature. A relationship among NMR signal peak value, substance content, pressure, and temperature is developed to estimate the hydration number of pore hydrates during hydrate dissociation. It is revealed that the hydration number (N h) of synthesized methane hydrates remains practically unchanged during hydrate dissociation in fine-grained sediments and is trivially influenced by experimental conditions, including initial pressure, density, initial water saturation, and salt content. Our experimental results indicated that the hydration number of methane hydrates is about 6.5, which is slightly higher than that of natural hydrates.

Thermal error of machine tool is the main in total machine tool error, and obviously impairs the accuracy of the machined workpieces. Ram is a very important component of heavy-duty floor type boring-milling machine, and its thermal deformation is a significant source causing errors in machining process. Aiming at the thermal elongation of heavy type milling boring machine tool ram, the machine tool thermal errors are measured and compensated. Temperature compensation function in NC system is applied. Experiment results shows that 90% ram positioning error can be compensated.

The purpose of landslide prevention and control is to keep the stability within a safe range. This paper proposes a new direction of landslide information prevention and control with BIM technology for soil landslide, which is a typical type of landslide. The BIM model was established by referring to the engineering geological parameters of typical soil landslides, and then several commonly used landslide stability calculations were compared and studied by using the model research method. On the basis of BIM model of typical soil landslide, the results of calculating related engineering geological problems by different stability calculation methods were verified, and the characteristics of different stability calculation methods were revealed. When several common methods were used to calculate the stability of typical soil landslides. How to select the appropriate methods for calculations is an inevitable problem whenever the stability evaluation of landslide prevention and control is carried out, so it is of important engineering value and significance for this research.

Internal high pressure forming is a kind of the modern plastic processing technology. Using liquid as the pressure transmitting medium, explore the effect of internal high pressure parameter on the three passing pipe technique, internal high pressure forming technique is applied on the three-dimensional shape parts deformation. In this study, we simulate the three-way pipe process by finite element software, analyze the forming force influence to the tube forming quality and get the changeable regulation of the pipe wall thickness with conclusion of the wall thickness variation, which provides the reference data and guidance for the actual production of the three-way pipe.