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On the basis of the Fengqi Chaoming project in Hangzhou City, Zhejiang Province, China, this paper investigates the influence of pile foundation construction on the existing tunnels in a metro protection area to ensure the stability and safety of the pile foundation construction in the area of Hangzhou Metro Line 2 through in situ pile tests and numerical simulations. The test results show that the pile foundation construction has a certain influence on the existing metro tunnels, and the degree of influence gradually decreases as the distance between the pile foundation and the metro tunnel increases. The corresponding impact level for the pile foundation at 12 m from the tunnel is 1.06 mm, and that for the pile foundation at 4.9 m from the tunnel is 1.18 mm. Different types of pile foundations also lead to different degrees of influence. The maximum settlement corresponding to triaxial cement mixing piles is 1.89 mm, while the hard-method occlusal piles is 1.18 mm. The monitoring point of the metro tunnel with the smallest distance from the pile foundation experiences the largest deformation, but several sets of deformation data meet the requirements of the deformation control index, indicating that the pile foundation construction is safe and controllable.

The pile foundation construction adjacent to an operational subway tunnel can induce the creep effects of the surrounding soil of the tunnel, resulting in the deformation of the existing tunnel lining and potentially compromising the safe operation of the tunnel. Therefore, the Mindlin solution and the generalized Kelvin viscoelasticity constitutive model were employed to establish the theoretical calculation model for the deformation of the adjacent subway tunnel caused by the pile construction. Then, the effect of pile construction on the deformation of adjacent tunnels under different pile–tunnel spacing was analyzed via three-dimensional numerical simulation and theoretical calculation methods and compared with the field monitoring data. The results showed that the theoretical and numerical data are in agreement with the field monitoring data. The theoretical model provides closer predictions to the field-measured values than the numerical simulation. As the distance between the pile and the tunnel increases, both the vertical settlement and the horizontal displacement of the subway tunnel lining exhibit a gradual reduction. In the hard plastic clay region of Hefei City (China), pile foundation construction near an operational subway tunnel can be classified into three distinct zones based on proximity to the tunnel: the high-impact zone (<1.0 D), the moderate-impact zone (1.0 D–3.0 D), and the low-impact zone (>3.0 D). The pile foundation in high-, moderate-, and low-impact zones should be monitored for 7 days, 3 days, and 1 day, respectively, to ensure the stable deformation of the lining.

In large-scale pile foundation drilling projects, the absence of digital work area management hampers dynamic construction management, affecting efficiency. This article explores multi-work area management during pile foundation drilling using a BIM parameterized model, focusing on informatization. The results indicate the following: (i) A dynamic zoning method for pile foundation construction using BIM models was developed to support information management systems and address resource allocation challenges amid dynamic construction team changes. (ii) Adaptive zoning methods were proposed, incorporating the dynamic adjustment of construction work areas, including the division of virtual work areas and adaptive adjustment of pile foundation partition parameters. (iii) Work area modeling and zoning were applied on site, with pile foundation modeling aligning with engineering design distribution, and work area zoning accurately reflecting the on-site construction status. (iv) This method enables adaptive synchronization between pile foundation model attributes and work area information, integrating zoning management into the information system to enhance the construction unit’s information management system and digital management level.

To improve the safety level of pile foundation construction for offshore wind power, in this study, the risk indicators of pile foundation construction were evaluated using the analytic hierarchy process (AHP) and comprehensive evaluation methods. The pile foundation construction operation process for offshore wind power mainly includes four phases: preparation for construction, pile sinking, end of construction, and foundation scour protection construction. Pile foundation construction risk indicators are systematically identified as human factors, material factors, management factors, and environmental factors. The most important indicators for pile foundation construction for offshore wind power were evaluated using AHP and comprehensive evaluation methods, which included five indicators: piling equipment, protective equipment, special skills, safety awareness, and emergency management. The four more important indicators are workplace environment, lifting equipment, fire protection systems, and operations. According to the results of our evaluation of the pile foundation construction safety indicators presented herein, corresponding recommendations are made that consider four aspects—human factors, material factors, management factors, and environmental factors. The construction industry should focus on improving the safety measures related to aspects with greater risk indicators. Pile foundation construction for offshore wind power can be evaluated using the method discussed in this paper, allowing industry stakeholders to prioritize and focus on improving safety measures related to aspects with greater risk indicators.

With the acceleration of transportation infrastructure and the densification of transportation networks, there has been an increase in bridge pile construction near oil and gas pipelines. Selecting bridge pile construction methods with minimal impact and reducing the adverse effects of bridge pile construction on nearby oil and gas pipelines are of great importance. This paper uses FLAC3D 6.0 software to simulate and analyze the impact of two different pile construction methods, rotary drilling and impact drilling, on adjacent oil pipelines. The results show that the horizontal displacement of oil pipelines during rotary drilling construction is nearly 90% lower than that of the traditional impact drilling method, and the axial stress is reduced by nearly 85%. Furthermore, numerical simulations of rotary drilling under different conditions were conducted to analyze and summarize the patterns of how different conditions affect construction vibration and stress. This study provides a reference for bridge pile construction near oil and gas pipelines or important buildings.

Taking the construction project of a new bridge pile foundation above an in-service subway in Xi’an as an example, considering the influence of horizontal symmetrical construction of pile foundation hole forming on the deformation of different sections of asymmetric tunnels, a three-dimensional finite element geometric model of pile-tunnel-soil is established based on ABAQUS software. Through the numerical simulation analysis of the structural deformation behavior of the in-service subway tunnel under the two construction stages of pile foundation hole forming and concrete pouring, the horizontal and vertical deformation laws of the key points of the in-service subway tunnel caused by the construction of the adjacent new pile foundation are analyzed from different angles.The calculation results show that: the deformation of the interval tunnel is mainly caused by vertical displacement, resulting in overall settlement of the tunnel. However, the settlement value is within a controllable range and does not affect the normal operation of the in-service subway tunnel. The concrete pouring stage has a greater impact on subway tunnels. The research work has important reference value for the reasonable safety monitoring and control of similar construction projects.

In view of the complexity of the pile foundation underpinning structure system and the stringent requirements of the construction process, this paper briefly describes the necessity of introducing epoxy resin reinforcing adhesive of planting rebar in the design of pile foundation underpinning beam structure to improve the mechanical properties of the reinforced beam new and old concrete joint surfaces and proposes a new type of pile foundation replacement beam system construction method by “chiseling + prestressed reinforcement + epoxy resin reinforcing adhesive”. This paper uses an actual pile foundation underpinning project of an urban overpass as a prototype, designs and creates a model structure with a similarity ratio of 1/6, and performs repeated progressive static loading tests to study the load carrying capacity, displacement change, and other properties of the strengthened replacement structure, as well as analyses and distorts the overall working performance and failure mode of them. On this basis, the prototype structure’s finite element analysis model was built, and the finite element analysis results were compared with the test results to obtain the mechanical properties and deformation characters of the actual pile foundation underpinning structure system corresponding to the actual underpinning beam load. This paper’s study can lay the theoretical and experimental foundation for the smooth development of similar projects.

This paper aims to investigate the effect of combined end-and-side grouting on the bearing properties of large-diameter rock-socketed bored piles in highly weathered rock layers. Eight full-scale pile load tests were conducted in the highly weathered rock layer to analyze the enhanced mechanism of the combined grouted bored piles. The test data from pile mechanical testing were compared with the recommended values in the current specification and geological survey report. The results demonstrate significant improvement in the side and end resistances of the combined grouted bored piles, resulting in a substantial increase in the bearing capacity and effective settlement control. It was observed that the construction of impact holes for bored piles can cause severe damage to highly weathered rock structures and weaken the mobilization of side and end resistances. Moreover, it was found that the calculation of the enhancement coefficient in the current specification underestimates the practical bearing capacity. The measured enhancement coefficients for the side and end resistance of piles in fully or highly weathered rock layers range from 2.49 to 3.05 and 2.24 to 2.43, respectively, which are more reasonable and feasible for the calculation. The research findings deepen the understanding of the bearing characteristics of large-diameter rock-socketed bored piles with combined grouting and provide valuable case references for the optimal design of large-diameter combined grouted piles for building foundations in Shenzhen, China.HighlightsPost-grouting had the potential to improve super high-building foundation reliability while reducing pile length and cost.The improvement effect and improvement mechanism of combined grouted bored piles embedded in highly rock strata were revealed.The influence of the size effect for large-diameter piles in highly weathered rock was revealed.The construction of impact holes for bored piles can cause severe damage to highly weathered rock structures and weaken the mobilization of side and end resistances.The enhancement coefficients for the side and end resistance of piles in fully or highly weathered rock layers were proposed.

In order to explore the influence of the different position of karst on the bearing capacity of pile group foundation, a theoretical analysis was carried out from the perspective of the reduction rate of pile group effect. Combined with the calculation method of pile foundation settlement, the calculation formula for pile group foundation settlement corresponding to different relative position conditions of karst caves was derived. Finite element numerical simulations were conducted using data from real pile foundation projects, and the results were verified with field measurements. The results demonstrate that the proposed method for analyzing pile bearing characteristics is widely applicable. When the karst cave is located beneath the central area of the pile foundation, the ultimate bearing capacity is relatively high. However, when the karst cave is located in the peripheral area, the ultimate bearing capacity decreases. The conclusions provide a theoretical basis and practical guidance for managing and controlling similar engineering problems.

Pile foundation is a commonly recognized form of foundation, and earthquakes are a common seismic damage phenomenon. Accidents resulting from reduction in pile bearing capacity due to earthquakes pose a great threat to people’s lives and safety. This article investigates the interaction between soil and piles under earthquake action. Utilizing the MIDAS GTS NX finite element software, the vertical bearing characteristics of piles under earthquake action are studied. Obtained acceleration of piles, pile settlement, pile axial force, pile top horizontal displacement, soil pore water pressure, and pore pressure ratio under different earthquake magnitudes. The research results indicate that as the depth increases, the acceleration at the pile top is significantly greater than that at the pile bottom, with an average increase of 20% in acceleration at three different earthquake magnitudes; Both the beginning of the pore pressure ratio growth and the ultimate reaching of its stable pore pressure ratio coincide with a rise in earthquake magnitude. Additionally, the axial force of the pile body also increases with the magnitude of the earthquake, and the maximum axial force of the pile body can increase by 40% at the same time. Simultaneously, the magnitude of the earthquake influences both the displacement of the pile body and the settling of the pile top. This article can provide reference for pile foundation design and engineering construction in liquefaction sites.