To ensure the safety of formwork engineering, and to accurately calculate the lateral pressure of fresh concrete on formwork, the problems of the formulas for lateral pressure of fresh concrete on formwork, provided by the national current standards, were analyzed firstly. Subsequently, based on the basic physical quantities of the international system of units, five key factors affecting the lateral pressure of fresh concrete on formwork were identified, the range of concrete slump was emphatically analyzed. By taking concrete slump as an important factor, it was directly introduced into the derivation. According to the relation between the depth of the concrete from the top of the placement to the point of consideration in the formwork, and the product of the rate of placing concrete in forms and initial setting time, formula for calculating the lateral pressure of fresh concrete on formwork was derived. Finally, the accuracy of the proposed formula was verified by using the experimental data in the literature. The results show that the proposed formula accords with the results of dimensional analysis, and the formula is more accurate in the application range of the formula provided by the national current standards. Moreover, beyond the applicable range of the formula provided by the national current standards, the proposed formula is of high accuracy and is generally safe.

The accurate prediction of soil compaction parameters has practical significance for improving soil bearing capacity and reducing compressibility in geotechnical engineering. The existing models have certain limitations in prediction progress and engineering applicability, and ignore the quantification of model prediction uncertainty. Genetic programming (GP) was used to model and predict two important soil compaction parameters (optimal water content and maximum dry density) for 226 groups of soil compaction test data with extensive and representativeness. The optimal display models of optimal water content and maximum dry density were obtained respectively, and the prediction results were compared with the results of existing prediction models. The GP model was quantified by combining quantile regression method and uncertainty statistics. The results show that the compaction parameters are most affected by fine grain content and plastic limit, while the gravel content and liquid limit have the least influence on them. Therefore, in practical engineering, the optimal compaction effect can be achieved by preferentially adjusting the fine grain content and plastic limit, while the gravel content (CG) and the liquid limit have the least influence on them. Therefore, in practical engineering, the optimal compaction effect can be achieved by preferentially adjusting the fine grain content (CF) and the plastic limit in the soil. In addition, the quantile regression (QR) method provides 90 % confidence and the mean prediction interval (MPI) is less than 0.3.At the same time, most of the data fall within the range of uncertain bands, indicating that the GP algorithm has strong prediction ability and high prediction accuracy. This interpretable display model is more convenient for engineering applications.

The applicability of prefabricated subway station structures in inclined liquefiable sites was investigated. Based on the actual project of Shuangfeng subway station in Changchun City, the finite difference software FLAC3D was used to carry out the seismic response analysis of prefabricated subway station structures in liquefiable soil, for example, the pore water pressure of the foundation, the lateral motion of the liquefied soil, the dynamic response and uplift characteristics of the subway station structure, and the deformation characteristics of the prefabricated subway station structures were analyzed. The results show that the negative pore pressure phenomenon of pore water pressure on both sides of prefabricated subway station under inclined liquefiable site conditions is present, and the phenomenon becomes more obvious the closer the location of the station structure is to the station, and at the same time, the negative pore pressure of the soil on the left side of the structure (uphill) is significantly greater than that on the right side (downhill). The further away the foundation soil is from the station structure, the more pronounced the liquefaction is. The phenomenon of lateral slippage of the surrounding soil is significantly suppressed by prefabricated subway station structures. The principal stresses in the upslope sidewall (member C1) are greater than those in the downslope sidewall (member C2), and the principal stresses at the bottom of the upslope sidewall of the structure are greatest, so the upslope sidewall of the structure should be given priority in the seismic design.

In order to prevent and control the snow drifting disaster along the Karamay-Tacheng Railway in northwest of Xinjiang, numerical simulation method was adopted to study the influence of different height and angle parameters of wind deflector on the snow flow field around a given railway embankment in 50-year recurrence period in this paper. The results show that increasing the angle between the wind deflector and the prevailing wind direction will weaken its effect on snow dispersion in the 50-year recurrence period. When the angle is set to 60°, the snow dispersion effect is the best. Increasing the height of the wind deflector will increase the coverage of the acceleration zone, which is more conducive to disperse snow flow and reduce the probability of snow particle accumulation. When the height is set to 2 m, it's a cost-effective solution.

With respect to the surrounding rock collapse and water gushing in the water-rich fault, a high-speed railway tunnel in Yunnan was taken as the engineering background. The fluid-solid coupling numerical calculation of tunnel construction with the three-step method was carried out, and the deformation mechanism and groundwater seepage law of surrounding rock through water-rich fault were researched combined with the deformation field monitoring results. The results show that when the tunnel face is excavated to the water-rich fault, the rock and soil in the upper wall of the reverse fault will collapse downward, and the settlement of the arch roof will increase sharply. At the fault, the rock and soil mass of the middle and lower excavation parts cannot provide stable support for the surrounding rock, so the tunnel clearance increases first and then decreases. The groundwater mainly percolates along the step surface and the palm surface, and there is still a large pore pressure above the tunnel, so the drainage pipe can be added to lead the water into the side ditch.

To analyze the main influencing factors and pathways of low altitude travel intention, a structural equation model was constructed based on travel intention model and value risk analysis. The interaction mechanism between travel preference, travel characteristics, perceived value, and perceived risk on low altitude aircraft travel intention was quantified. The path coefficients were solved using unweighted least squares method, and the mediating effects of perceived value, perceived risk, and other factors on travel preference were analyzed. Additionally, a multi group model invariance analysis of individual information such as gender and age on travelers was conducted.Finally, the fuzzy set qualitative comparative analysis (fsQCA) method was used to analyze the configuration of the antecedent variables of travel intention. The results showed that the chi square degree of freedom ratio, RMSEA (root mean square error of approximation)value, and CFI(comparative fit index) value of the structural model were 3.803, 0.063, and 0.938, respectively, which passed the model validation. Perceived value (0.38) is the most important factor affecting travel intention. Travel characteristics (0.08) have a positive direct impact on travel intention, while perceived risk (-0.22) has a negative direct impact. However, travel preferences have no significant impact on travel intention; Travel preferences have a negative effect on travel willingness, but travel characteristics and perceived value have a masking effect on travel preferences, while perceived risk has a mediating effect on them; The pre tax annual income in the individual information of travelers has a moderating effect on the model. As the travel distance increases, the high-income group is more willing to use low altitude aircraft than the low-income group. At the same time, the high-income group is more sensitive to the perceived risks of low altitude aircraft in terms of technological maturity and accident severity. fsQCA analysis shows that there are three configurations that can form travel intention, among which configuration 3 ( type of travel characteristics&perceived value) has the highest sample coverage, explaining 48.9% of the sample cases. When travelers are necessary to travel during peak hours and have a positive understanding of low altitude travel comfort, privacy, etc., they will develop a low altitude travel tendency. The research findings can provide data support for the promotion and policy formulation of low altitude aircraft.

The structure and materials used in bridge deck pavement layers significantly impact their road performance. To design a pavement layer more suitable for cold regions, the layered modification of pavement materials was optimized based on the principle of layer function design. Firstly, materials for the surface functional layer and overall functional layer were selected using the layer function division, with lignocellulose and polyester fibers as modifiers, respectively. Secondly, the appropriate content of polyester fibers was determined through road performance tests. Finally, the choice of layered materials and appropriate modification methods were established. The results indicate that both the surface functional layer and the overall functional layer should use the same high-viscosity, high-elasticity modified asphalt, with lignocellulose and polyester fibers as modifiers, respectively. This approach avoids differences in thermal contraction coefficients of the layered materials, ensuring coordinated thermal deformation between the pavement layer and the bridge structure, thereby effectively improving the road performance of the asphalt bridge deck pavement. Furthermore, under engineering economic requirements, when the polyester fiber content is 1% of the total mixture mass, the prepared asphalt mixture's high-temperature performance increases by 7%, low-temperature performance by 23%, and water stability by 5%.

In order to further analyze the visual characteristics and risk conditions of drivers at the confluence sections of entrance ramps at adjacent urban underground roadways, data collected from real-vehicle experiments were used. A linear fitting model was constructed and the pupil area growth rate was calculated to investigate the patterns of pupil area changes. The K-medoids clustering method was employed to classify the regions of interest in drivers' gaze patterns, and the characteristics of drivers' gaze behavior were analyzed. A game theory-extension cloud evaluation model was constructed to evaluate the driving risks at the confluence sections of entrance ramps at adjacent urban underground roadways. The results show that the pupil area increases linearly in the entrance section and decreases linearly in the exit section. The overall load follows the order of adjacent entrance confluence section > adjacent entrance split section > adjacent exit split section > adjacent exit confluence section. Additionally, drivers face certain driving risks due to various factors at the confluence sections of entrance ramps at adjacent urban underground roadways. Based on the evaluation and actual survey, the risk factors for each section were analyzed, and optimization and improvement suggestions were proposed.

In order to explore the impact of altitude on the emergency evacuation of aircraft passengers at airports, a simulation model for emergency evacuation of aircraft accidents at airports was built. By introducing panic factor, age factor, gender factor and altitude correction factor, passenger walking speed at different altitudes was quantitatively characterized, and passenger evacuation effects were analyzed under conditions such as different altitudes, with or without evacuation guidance, and cabin aisle spacing, dual aircraft evacuation. The results show that the impact of emergency evacuation time in a high plateau environment is mainly reflected in the middle and late stages of cabin evacuation and ground evacuation. When the altitude is 4 280 m, the cabin evacuation time is increased by 19.6 s and the overall evacuation time is increased by 44.1 s compared with the plain area. By setting cabin crew guidance, cabin evacuation time is reduced by 18.1 s and evacuation efficiency is increased by 16.5%. When the width of aisle spacing is increased to 60 cm, the evacuation time in the cabin is reduced by 20.8 s, and the evacuation efficiency is increased by 19%. Compared with single-aircraft evacuation, the evacuation time of dual-aircraft evacuation is significantly increased, so it is necessary to optimize the evacuation strategy. The research results can provide theoretical support for the optimization of aircraft emergency evacuation schemes at high plateau airport.

In order to more accurately predict flight delays at different times of the year,flight delay prediction trends was investigated using operational and meteorological data from Atlanta Airport in the United States for the year 2023. A CA-PCA-Informer flight delay prediction model,incorporating correlation analysis (CA),principal component analysis (PCA),and the Informer model,was proposed. Mean absolute error (MAE) and root mean square error (RMSE) were utilized as evaluation metrics to assess the prediction error. The findings reveal that the CA-PCA-Informer model outperforms simpler combined models,demonstrating the lowest error compared to the CA-PCA-LSTM and CA-PCA-GRU models,with MAE and RMSE reductions of 20.2%~20.7% and 12.7%~14.1%,respectively. The CA-PCA-Informer model is particularly effective for one-hour ahead predictions,providing decision-makers with more accurate flight delay trends to enhance efficient flight operations.