This paper presents a simple method to predict the settlement of the composite foundation with sparse prestressed tubular concrete (PTC) capped-piles under embankment. In this study, it is assumed that the distribution of skin frictions on PTC capped-piles is simplified as two force triangles, and a calculation model for predicting the additional stresses in the composite foundation soil is given. By combining Mindlin-Geddes and Boussinesq solutions, the equation of the additional stresses for a single PTC capped-pile foundation is derived considering the influence radius. A case history involving the installation of sparse PTC capped-piles for soil reinforcement under highway embankment is introduced, with a maximum settlement of 428 mm after construction. The predicted settlements of the composite foundation, resulting from the proposed method, are in good agreement with the observed data. Additionally, the additional stress field calculated shows a little change because the pile spacing is eight times larger than the pile diameter. Thus, the proposed method can optimize the design of the foundation soil reinforcement resulting from PTC piles.

When horizontal jet grouting is conducted in fine-grained soils, the injection of large volumes of fluid with high injection pressure into the ground may cause ground surface upheaval and the lateral movement of subsoil. This paper provides a numerical approach to calculate the ground displacement caused by installing a horizontal column based on determination of the influencing radius of injection pressure and the volumetric expansion strain caused by fluid injection. During the course of this study, the relationship between the influencing radius, column radius, volumetric expansion strain, and jetting parameters is established. The proposed numerical approach is applied to analyze a case history conducted in Shanghai soft soil deposits, which include the monitoring of vertical displacement of the ground surface and lateral displacement of the subsoil during construction. A comparison of the results between the simulated values with the Mohr Coulomb model and field data demonstrates that the numerical approach can yield a reasonable prediction of these field measurements when the influencing radius is six times the radius of the column. The influence range of the horizontal jet grouting activity is also discussed by numerical analysis with respect to two soil models (the Mohr Coulomb model and the hardening soil model).

To reduce the enormous waste of electric energy in tunnel lighting, an intelligent control system of road tunnel lighting which can realize the effect of illumination moving with the vehicle is proposed. In this system, the group control of LED lamps is realized based on Air Lamp lighting technology through the wide area fusion Internet of Things (WF-IoT). By the group control of LED lamps, the tunnel lighting is divided into several illumination segments. When the vehicle is detected by the surveillance camera, the corresponding LED group can be adjusted to the demand luminance according to the environmental conditions and traffic information. The other LED groups maintain 10% of the maximum luminance to reduce energy consumption. To realize the effect of illumination moving with the vehicle, the structure of the intelligent control system and hardware system is designed, and the length of the illumination segment is calculated. To evaluate the lighting effect of the intelligent control system, a simulation model of tunnel lighting is established. In addition, the energy-saving effect of the intelligent control system is evaluated. The results show that the intelligent control system can meet the requirements of illumination in a tunnel and have a notable energy-saving effect.

In tunnel construction, the difficulty of ventilation gradually increases with the increase of ventilation distance, which endangers construction safety and delays construction progress. This paper presents an air cabin ventilation system of the tunnel during construction. Theoretical calculations show that the energy consumption of this ventilation system is reduced by 20.7% compared with blowing ventilation, especially since the resistance loss along the air duct is reduced by 47.04%. A 3D numerical model validated with field test data was employed to discuss the air cabin structural parameters on the ventilation efficiency of the axial fan. The results show that the relative pressure on the fan’s end face increases when the air cabin’s length–width ratio is R = 1:2. The fan spacing S = 2–4 m can ensure the larger relative pressure of multiple fans. The significant difference in air demand between the left and right sides causes the disordered airflow. Set a middle diaphragm length of 1.5 D in the air cabin, which can effectively reduce the phenomenon. The middle diaphragm with a radian of 30°effectively reduced the local loss by 59.40%. The proposed ventilation system shortens the ventilation distance and has the advantages of low energy consumption and resistance loss. It improves the construction environment and is a valuable means of ventilation design for tunnel construction.