Pervious concrete is an environmentally friendly material that improves water permeability, skid resistance, and sound absorption characteristics. Permeability is the most important functional performance for the pervious concrete while limited studies have been conducted to predict permeability based on mix-design parameters. This study proposed a method to combine the beetle antennae search (BAS) and random forest (RF) algorithm to predict the permeability of pervious concrete. Based on the 36 samples designed in the laboratory and 4 key influencing variables, the permeability of pervious concrete can be obtained by varying mix-design parameters by RF. BAS algorithm was used to tune the hyperparameters of RF, which were then verified by the so-called 10-fold cross-validation. Furthermore, the model to combine the BAS and RF was validated by the correlation parameters. The results showed that the hyperparameters of RF can be tuned by the BAS efficiently; the BAS can combine the conventional RF algorithm to construct the evolved model to predict the permeability of pervious concrete; the cement/aggregate ratio was the most significant variable to determine the permeability, followed by the coarse aggregate proportions.

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Coal pyrolysis under high-temperature and high-stress conditions was studied experimentally in this work. Which experimental table should be chosen was studied, and parameter settings such as the final pyrolysis temperature, heating rate, and stresses were investigated. Pyrolysis experiments of Xinglongzhuang gas coal and Huating long-flame coal were conducted using an improved Paterson gas-medium high-pressure and high-temperature testing (Paterson HPT) system at temperatures of up to 1000 °C and under different stresses conditions. The results were compared to those of coal pyrolysis experiments without any stress and using a GR.TF80/11 tube furnace. The average heating rates used in these experiments were as low as 0.44 K/min. The produced gas and semicoke (coke) yields both increased with increasing stress, while the tar yield decreased. However, the variations in the yields of the pyrolysis products induced by the same increase in stress gradually decreased as the stress increased and nearly reached a peak at approximately 750 °C. The concentrations of CH 4 and CO 2 in the pyrolysis gas gradually increased with increasing stress, while the H 2 and CO concentrations gradually decreased. Regarding the variations in H 2 , CO, CH 4 , and CO 2 , the Huating coal displayed significantly more variations than the Xinglongzhuang coal for the same increase in stress, indicating its higher sensitivity. The variation curve for each gas component under each stress state was similar to the corresponding curve in the stress-free state, indicating that temperature is a dominant factor in coal pyrolysis and that the effects of stress-induced secondary reactions are relatively small.

Vibrations induced by traffic are of concern for the slope stability of the open-pit mine. Different solutions to mitigate this phenomenon are under investigation. In the field of pavement engineering, the so-called antivibration paving technologies are under investigation in order to avoid the generation of excessive vibration and contains propagation. To more fully examine the effectiveness and potential of the antivibration pavement in the application of vibration absorbing for the open-pit mines, numerical simulations based on a two-dimensional (2D) finite element (FE) model were conducted. Sensitivity analysis of varying monitored points and varying loads are performed. Several important parameters such as the damping layer position and thickness and damping ratio are evaluated as well. By using this FE simulation to model the vibration response induced by traffic, the costly construction mistakes and field experimentation can be avoided.