Pengyuan Zhou specializes in the field of geotechnical engineering, with research interests spanning various types of tunnels, slopes, and excavation projects. His primary focus lies in rock mechanics and soil mechanics, utilizing numerical simulations, theoretical analyses, Machine Learning/Neural Networks, and model experiments to investigate the deformation characteristics of geotechnical materials after excavation.
Dr. Zhou provides critical design parameter recommendations for underground construction projects, optimizes construction processes, and advises on safety measures to ensure secure project implementation.
As a peer reviewer for several international journals and an active member/expert within professional organizations, Dr. Zhou has contributed significantly to advancing geotechnical engineering research. He has also been invited to participate in numerous international conferences, reflecting his influence and expertise in the field.
Tunnel engineering rock mechanics soil mechanics numerical simulation theoretical calculation neural networks data analysis
The transfer section between the cross passage and the main tunnel is the part that needs to be paid attention to during the underground excavation construction of the subway. Due to complex stress, the collapse of the horsehead gate and excessive surface settlement often occur. In order to determine the construction scheme of the transfer section between the cross passage and the main tunnel of Guanshui Road Station of Metro Line two in Guiyang, China, the numerical simulation method was used to analyze the “double-holes interval pillar method,” “sector expansion method,” and “gate climbing method,”, respectively. The mechanical response of the surrounding rock and supporting structure under each method was compared. The comparisons showed that the surface settlement, the displacement of the cave, and the plastic zone caused by the double-holes interval pillar method were the smallest, and the method can reduce the construction risk, shorten the construction period, and reduce the project cost. Therefore, it was recommended to use the double-holes interval pillar method to construct the transfer section. The comparison between the measured data and the numerical simulation results of the double-holes interval pillar method showed that the numerical simulation results were smaller than the measured data at each point, and the surface settlement and horizontal displacement in the tunnel both met the safety control standard.
The influence of tunnel excavation on adjacent buildings or structures must be considered when new tunnels pass through existing buildings or structures. In this article, based on the project of the Aotidong-Aotizhongxin section of Shenyang Metro Line 9 passing through the existing Aotizhongxin station of Line 2, the numerical simulation was employed to research the settlement laws of the existing station’s baseplate by four methods, namely the full-face excavation method, the benching tunneling method, the side heading method, and the center diaphragm (CD) method. Based on the results of numerical calculations, in order to ensure the safe and normal operation of existing station, it was recommended to use the CD method to construct the new tunnels. At the same time, the advanced deep hole grouting reinforcement technology and jack-up technology should be adopted in the process to reduce settlement of the station’s baseplate. The CD method proved applicability in the project by comparing the field-monitoring data with the numerical calculation results. The results can provide reference for the design and construction of similar projects in the future.
Underground engineering construction is facing increasingly complex geological conditions and engineering challenges, such as surrounding rock deformation and lining cracking, that seriously threaten the safety of tunnel construction and operation. Aiming at these problems, a pipeline tunnel crossing jointed expansive mudstone strata was taken as an example, and the disaster characteristics of surrounding rock and lining were analyzed through field investigation. The disaster-causing mechanism and corresponding control measures were studied through laboratory tests and numerical simulations, which were then applied to actual construction. Meanwhile, the deformation and stress response of the surrounding rock and tunnel structure were analyzed and investigated through monitoring and numerical data. The results showed that the vault settlement and horizontal convergence deformation of surrounding rock were reduced by 64.69 mm and 54.74 mm, respectively, under the improved construction scheme. The maximum surrounding rock stress was 430.26 kPa under the improved construction scheme, which was 18.15% lower than the original stress. The maximum axial force of the steel arch frame was 33.02 kN, ensuring the stability of the supporting structure and tunnel construction safety. Finally, the rationality and effectiveness of the reinforcement measures adopted were assessed.
Taking the foundation pit of the Suzhou Chunshenhu Road Expressway Reconstruction Project as an example, the excavation process of the foundation pit was numerically simulated using a three-dimensional finite element method. The measured data and simulated data of the lateral deformation of the enclosure structure, surface settlement deformation of the ground outside the pit, and settlement deformation of the building were compared to analyze the impact of foundation pit construction on adjacent buildings. The influence of foundation pit floor and diaphragm wall thickness on wall displacement, building settlement, and foundation pit uplift was also discussed. The results showed the following: (1) Adding a foundation pit floor has a significant effect on reducing the lateral displacement of the diaphragm wall, settlement of the building, and uplift of the foundation pit. Increasing the thickness of the foundation pit floor has a limited effect on reducing the displacement, while increasing the thickness of the diaphragm wall has a small effect. (2) The displacement curve of the underground diaphragm wall increases with depth. It reaches a maximum at the excavation surface and then decreases gradually. (3) The surface settlement increases first and then decreases with distance from the foundation pit, showing a concave shape. As the depth of excavation increases, the settlement value increases. (4) Through analysis of the monitoring data of vertical displacement of buildings, it can be seen that during foundation pit excavation, buildings undergo five stages: initial slow descent, steep descent, mid-term slow descent, late steep descent, and stable deformation. The buildings are dominated by settlement deformation.
Laboratory triaxial tests are essential for studying sandy soil behavior but have limited ability to capture localized deformation and microstructural evolution. The discrete element method (DEM) overcomes these limitations by enabling particle-scale analysis, where boundary conditions can critically affect simulation results. This study employed DEM-based triaxial compression simulations to compare rigid wall and flexible membrane boundaries for sand specimens with initial porosities of 35.5%, 38.2%, 40.8%, and 41.5% under confining pressures of 50, 100, and 150 kPa. The analyses covered macroscopic stress–strain and volumetric responses, shear band morphology, local porosity evolution, and contact force fabric. The results indicate that rigid and flexible boundaries produce similar pre-peak responses, but differ markedly in post-peak behavior and volumetric strain. Rigid boundaries constrain lateral deformation, induce stress concentrations, and underestimate post-peak strength, while flexible membranes apply confining pressure more uniformly and reproduce realistic bulging and porosity evolution. Based on these findings, rigid boundaries are suitable for dense sands when post-peak strength is not a concern, and for loose sands at small strains, whereas flexible membranes are necessary to capture volumetric contraction and realistic post-peak responses. This work provides mechanistic insights into boundary effects and offers a basis for more efficient selection of boundary conditions in DEM triaxial simulations.
