Pile Installation Research Articles

Analysis of prevention measures for the environmental effect of vacuum combined surcharge preloading

Abstract Soft soil is widely distributed in the Pearl River Delta region of China. In the process of treating soft foundations, it is important to consider not only the effect of preloading consolidation but also the impact of construction on the surrounding environment. This article focuses on the soft foundation reinforcement treatment project of a municipal road in Hengqin, Zhuhai, and utilizes finite element software ABAQUS to establish a vacuum-combined preloading soft foundation reinforcement model. Six working conditions are set up for two prevention and control measures: digging side ditches and driving cement mixing piles. The changes in soil deformation caused by these measures are analyzed with different distances from the reinforcement area boundary, different ditch depths, and different pile lengths. The results indicate that excavating side ditches and installing cement mixing piles can effectively reduce deformation of the outer soil. As distance from the side ditch (or cement mixing pile) increases, their weakening effect on deformation gradually decreases. Excavating side ditches can achieve a weakening effect within 8-10 meters outside the ditch, while installation of cement mixing piles has an approximate range of 7-10 meters on both inner and outer sides of the piles. Furthermore, excavating side ditches shows better reduction in horizontal displacement compared to driving cement mixing piles at a lower cost. These research findings provide valuable insights for widespread application of vacuum-combined preloading methods in soft foundation treatment within the Pearl River Delta region.

Protecting a complex intertidal habitat in the Severn Estuary affected by jetty construction

This case study presents a coastal engineering scheme that addressed a unique environmental challenge on a marine construction site. Artificially bunded reservoirs were constructed on the rocky shore of the Bristol Channel, UK, to mitigate the potential impact to ecological features of the Severn Estuary/Môr Hafren Special Area of Conservation resulting from the construction of a jetty at the Hinkley Point C construction site. The installation of piles irreversibly altered the natural supply of seawater from several large rock pools to Corallina officinalis (red seaweed) waterfalls, that the developer, Electricité de France, was obliged to protect. Corallina can die within 30 min of drying out. Following rigorous topographic surveys of the foreshore, hydrodynamic modelling and an evolution of protective measures, concrete structures were designed and installed to ensure the Corallina waterfalls were passively supplied with a constant flow of seawater throughout the tidal cycle. The artificial bunds had to be sympathetic to the natural environment while sufficiently durable to withstand the high-energy conditions of the intertidal site. A local wave buoy 13.5-year dataset shows that the scheme has withstood the two highest wave heights recorded, one of which was the third highest storm peak.

Lateral Effects of Jet Grouting on Surrounding Soil and Circular Diaphragm Walls

The installation of high-pressure jet grout piles induces significant lateral soil displacement, which can adversely affect nearby structures, such as diaphragm walls. Based on field tests, this study systematically analyzes the lateral displacement of soil caused by two distinct grouting techniques: the intelligent sensing super jet pile (SJT) technique and the Rodin jet pile (RJP) technique. Experimental results show that the SJT technique induces less disturbance to surrounding soil, with a maximum lateral displacement of approximately 6 mm at the closest inclinometer and an influence range limited to about 4 m. A theoretical model, based on passive pile theory, was developed to predict the lateral deflection of diaphragm walls due to adjacent jet grouting. Using a finite difference algorithm, bending moments on the walls were calculated and compared to measured data, showing a consistent correlation between predictions and observations. These findings are crucial for the design and construction of jet grout piles near sensitive structures, ensuring the safety and reliability of soil improvement practices and underground engineering.

In-Depth Analysis of Low-Cost Micro Electromechanical System (MEMS) Accelerometers in the Context of Low Frequencies and Vibration Amplitudes.

Shock and vibration hazards to civil structures are common and come not only from earthquakes but most often from mining operations or foundation work involving the installation of piles using hammer-driving and vibrating technology. The purpose of this study is to present test methods for low-cost MEMS accelerometers in terms of their selection for low-amplitude acceleration vibration-prone object-monitoring systems. Tests of 24 commercially available digital accelerometers were carried out on a custom-built test bench, selecting four models for detailed tests conducted on a specially built precision vibration table capable of inflicting accelerations at frequencies of 1-2 Hz, using displacements as small as a few micrometers. The analysis of the results was based, among other things, on a modified method of determining the signal-to-noise ratio (SNR) and also on the idea of the effective number of bits (ENOB). The results of the analysis showed that among low-cost MEMS accelerometers, there are some that are successfully suitable for the monitoring and warning of excessive vibration hazards in situations where objects are extremely sensitive to such impacts (e.g., treatment rooms in hospitals). Examples of accelerometers capable of detecting harmonic vibrations with amplitudes as small as 10 mm/s2 or impulsive shocks with amplitudes of at least 70 mm/s2 are indicated.

Progressive failure mechanism of existing-supplementary double-layer piles retaining excavation beneath existing underground space

The increasing degree of urbanization has resulted in traffic and space congestion. When there is no longer any aboveground space for development, the existing space underground is excavated, and the construction of underground buildings is expected to solve the above problems. In the excavation of an underground layer, it is necessary to drive supplementary and existing piles into the soil to form a double-layer pile-supported structure. Aiming at an existing–supplementary double-layer pile-supported structure and considering the pile spacing of the supplementary piles, use of crown beams, and other factors, this study performed a series of indoor model tests and an simulation analysis in combination with finite element analysis software to reveal the bearing characteristics of this structure. The results showed that the installation of supplementary piles could effectively inhibit soil slippage after pile driving, redistribute the soil pressure load of the existing piles, and reduce the number of soil cracks between the piles. With the increase in the supplementary pile spacing, the deformation of the existing–supplementary double-stacked piles gradually intensified, and the bending moment of the pile body and the horizontal displacement at the top of the piles increased. The installation of crown beams in the existing piles could strengthen the connection between the existing and supplementary piles, reduce the number of soil cracks between these piles, and change the force mode of the pile body. Considering the geological conditions and the influence of existing buildings, the deformation laws of the supporting structure and the soil around the foundation piles during the excavation of an underground layer of an L-shaped foundation pit were revealed. The research results are expected to provide a scientific and theoretical basis for the design and construction of downward additional support structures for existing buildings, along with socio-economic significance.

Development of a mini vibro-driver for pile testing in the centrifuge

Using vibro-installation to fully install monopiles for offshore wind turbines (OWT) has the potential to mitigate pile run, significantly reduce noise emissions to the marine environment, and decrease project costs. However, due to the inherent complexity of vibro-installation and the limited quantitative data available in the public domain, the mechanisms underpinning vibro-driving are not fully understood. This results in uncertainties in engineering predictions of vibro-drivability and the post-installation performance of monopiles. To address these issues, an innovative mini vibro-driver, designed specifically for use in a geotechnical centrifuge, was developed to study vibro-installation and the lateral loading response of monopiles in sand after installation. The paper outlines the challenges addressed in the design of the vibro-driver, its working principles, and its capabilities. Following this, the results from vibro-driven pile installation tests are discussed and provide an indication of the type and quality of data obtained. These data can contribute to improving the understanding of vibro-driving mechanisms and thereby improve future engineering predictions.

Experimental Study on the Time-Dependent Resistance of Open-Ended Steel Piles in Sand

Open-ended steel piles are commonly used as the foundation for offshore structures. Numerous model and field tests have demonstrated a time-dependent increase in the resistance of these piles, a phenomenon referred to as pile ageing or pile setup. Additionally, for open-ended steel piles with comparably small diameters, soil plugging enhances the resistance against axial compressive loads. Realistically predicting these effects is necessary for their reliable incorporation into design practice. This contribution presents static compression and tension pile load testing conducted in an experimental pit filled with wet, uniformly graded silica sand. In total, twelve piles (L= 5.5 m, Do= 325 mm) were driven into homogeneously compacted sand using a pneumatic impact hammer. Firstly, static compression pile load testing was executed at various times after installation. Subsequently, static tension pile load tests were carried out. The results of the static compression pile load tests indicate that the compressive resistance doubles over an ageing period of 64 weeks. The experimental investigations of the effect of soil plugging showed marginal soil plugging during pile installation, but a significant influence of the soil plug on the compressive resistance.

Performance Analysis of Pile Group Installation in Saturated Clay

In offshore pile engineering, the installation of jacked piles generates compaction effects within soil, thus further affecting previously installed adjacent piles. This study proposes a three-dimensional numerical model for pile group installation, soil consolidation, and loading analysis. Subsequently, the effect of pile spacing and pile length-to-diameter ratio on the deformation, internal forces, and vertical bearing capacity of adjacent piles are investigated. The results indicate that with an increase in pile center distance, the peak lateral displacement of the adjacent piles decreases, whereas the peak vertical displacement increases. As the pile length-to-diameter ratio increases, the peak vertical and lateral displacements of the adjacent piles are enhanced. In addition, the peak axial force of the adjacent piles initially decreases and then increases with the penetration depth of the subsequent pile, whereas the peak bending moment initially increases and then decreases. The vertical bearing capacity of the subsequent pile is significantly superior to that of the adjacent piles. Therefore, the effects of pile installation on adjacent piles should be included in pile engineering. The impact of the subsequent pile installation on the bearing capacity of adjacent piles can be significantly reduced by increasing the pile center distance and pile length-to-diameter ratio. The findings provide useful guidance for pile group engineering.

Road Site Inspection and Measures to Avoid Further Deformation

Strength and stability of the roadbed and engineering structures in permafrost conditions and deep seasonal freezing of soils always remain complex scientific, technical and technological problem in construction and reconstruction of roads in northern regions. Particularly important is the spread of subgrade subsidence during construction and further operation and maintenance of roads in these regions. The road destruction is mostly caused by both global warming and geological and hydrogeological conditions.To prevent the deformation development, it is necessary to provide a number of special engineering measures to prevent thawing of permafrost soils or strengthen supra-permafrost layers of foundations. The purpose of the work is to study methods for eliminating deformation of the road bed in permafrost and choosing the main method for eliminating subsidence of the road.The article discusses several ways to solve the problem of eliminating subsidence on of the federal highway. Options for reconstruction of the roadbed are considered. These are different methods of thermal stabilization, i.e., horizontal (sloping) thermal stabilization system with inclined thermal stabilizers, temporary vertical thermal stabilizers for pre-construction freezing of foundation soils, and hybrid thermal stabilization system (horizontal and vertical thermal stabilizer in one product). A method is proposed for stabilizing the road base by installing soil-cement piles. The main advantages of and disadvantages the methods are noted and cost assessment is made. A conclusion is drawn on the effectiveness of different methods to restore the subgrade structure in order to ensure the road base stability. The main method is elimination of subsidence by stabilizing the road base with installation of soil-cement piles.

Environmental Sustainability of Pile Construction Activities in Nigeria; Strategies and Best Practices

: Pile construction activities is a multifaceted activity among the construction activities that are performed by heavy machines, materials and energy sources generating environmental impacts associated with pilling activities such as carbon emissions, noise, heavy vibration, soil instability and groundwater pollution. Sustainable piling construction guarantees that the whole piling process meets environmental sustainability and ultimately human health and wellbeing. Data were gathered through a questionnaire survey administered to construction professionals including engineers, project managers, surveyors, and builders. Out of the 50 questionnaires distributed, 41 responses were analyzed. The study employed the Relative Importance Index (RII) to rank the effectiveness of various strategies in mitigating environmental impacts. The findings underscore the critical role of introducing low-emission machinery and optimizing operational hours in reducing carbon emissions. Noise management was most effectively achieved through alternative pile installation methods combined with regular equipment maintenance. Maintaining adequate setbacks from structures and employing controlled installation techniques were identified as essential strategies to mitigate vibration. Addressing soil instability was found to rely heavily on thorough site investigations and the implementation of effective ground stabilization techniques and preventing groundwater pollution requires the proper use of drilling fluids and diligent site management. These findings contributed to the development of environmentally sustainable practices in pile construction, emphasizing the importance of comprehensive strategies to mitigate the adverse environmental impacts of such activities in Nigeria.

Assessment of piles’ resistance driven sequentially in fine-grained soils using pile load tests

This paper presents a field pile load test program conducted on four 0.36 m closed-end steel pipe (CEP) piles with lengths ranging between 11 to 13 m installed in fine-grained soils. Subsurface investigations with standard penetration tests (SPT) and cone penetration tests (CPT) with pore pressure measurements were performed at the site. Three pushed-in piezometers at incremental offsets from the piles were also installed to monitor pore water pressure changes during and after the installation of piles. Several dynamic load tests (DLT) were performed at different times to observe the change in pile resistance. A static load test (SLT) was also performed on one of the piles. Some load test results showed an unexpected decrease in the resistances of some piles with time. The study showed that construction activities, e.g. installation of other piles, disturbs the soil and groundwater conditions which can significantly affect the pile resistance measured during load tests. This investigation revealed that pile driving and restrikes should be scheduled such that the effect of construction activities on load tests results will be avoided or minimized.

An efficient model for underwater noise prediction during pile driving.

Underwater noise pollution from pile driving is now attracting increasing attention. However, most of the current numerical and semi-analytical models for predicting the noise are still expensive and time-consuming, and the near-field noise and far-field noise have to be obtained from different models. This paper proposes an efficient semi-analytical solution for predicting underwater noise in both near field and far field with only one model, whose computational efficiency is orders of magnitude higher than that of the finite element model. It is the first time that the Baranov-Novak thin-layer model for soil-pile interaction has been extended to the subject of underwater noise prediction during pile installation, taking into account pile-fluid-soil interaction. The solutions are obtained using the Laplace transform and the variable separation method. By comparing the prediction results with the five reported research cases, it is shown that the error of the proposed model is within reasonable limits for both near-field and far-field noise predictions.

Underwater sound from rotary oscillator and pile driving construction activities - I-205 Bridge over the Willamette River - I-205 Abernethy Bridge, Oregon

The Oregon Department of Transportation (ODOT) is conducting construction work in the Willamette River that involved the installation of piles through the water. There is a potential for impacts to wildlife, primarily fish, due to high noise levels. The project added piers to the existing bridge that consist of 12-foot diameter pile casings and drilled shafts. These casings are installed through rotary-oscillation drilled shafts that extended well below the water. These piles extend 200 feet below the river bottom. A large rotary oscillator was required to install the casings, which was supported on temporary platforms constructed in water. The platforms were supported by hollow 36-inch diameter steel piles. Underwater sounds from rotary oscillators have not been measured extensively in the past. This paper describes the underwater sound levels and characteristics of drilling large diameter casings deep through the substrate using the rotary oscillator. Measurements were also conducted for impact pile driving sounds from installation of the 36-inch diameter piles. The sound measurements evaluated the effectiveness of air bubble curtains meant to reduce sound from impact pile driving and meet permit requirements to minimize exposure of fish to harmful sound levels.

Down-the-hole drilling construction acoustic research

nd The Alaska Department of Transportation and Public Faculties (DOT&PF) is conducting research to characterize underwater sounds from down-the-hole (DTH) drilling activities. This method of drilling is commonly used to drill holes through hard or rock substrates to support piles or tensions anchors for piles. A pneumatic DTH hammer is driven by pressured air coming from an air compressor that provides the energy to power the percussion piston that hits the drill bit with a specific impact frequency and energy to break the rock and advanced the hole. This activity produces continuous and impulsive sounds that affect marine mammals. Pile installation in marine environments typically uses vibratory drivers and/or impact pile driving. Underwater sounds from these activities have been well documented in publications, for example, there are compendiums prepared by Caltrans, and the U.S. Navy, along with many project-specific compliance reports submitted to resource agencies. However, there is limited acoustical data available for DTH activities, as the first published measurements were only made recently. The National Marine Fisheries Services (NMFS) recognizes the acoustical issues with DTH noise and is encouraging the collection and dissemination of additional sound data. This paper describes the research conducted and available DTH acoustic data.

Prediction of Pile Running during Installation Using Deep Learning Method

Pile running during the installation of offshore large diameter pipe piles poses a significant challenge to construction safety and pile bearing capacity. This paper proposes a deep learning (DL)-based method for predicting pile running occurrences. Utilizing a dataset of pile installation records collected from various construction sites, the DL model was trained and tested. The predictive capacity of the DL model was compared with conventional analytical methods, demonstrating its superior performance in terms of accuracy and robustness. Additionally, the SHAP (SHapley Additive exPlanations) method was employed for the sensitivity analysis of the model’s input variables, and the resultant importance ranking agreed well with the findings of existing studies, thus enhancing the reliability and interpretability of the model’s predictions.

The Investigation of Stability on Slopes Utilizing Reinforcement Gabion Walls and Concrete Piles for Mitigating Landslide Disasters

Introduction Landslides frequently occur along roads crossing mountainous terrain during the rainy season, posing a significant risk of severe disruption to land transportation routes. Efficient and accurate resolutions are essential in managing landslides to facilitate immediate transportation recovery, such as gabion walls and pile installation. Aim This article aimed to evaluate the effect of installing gabions and piles for safety measures on the stability of slope landslides. The analysis of slope stability was performed utilizing the Plaxis 2D software. For reinforced slopes, the Safety Factor (SF) value utilized as a benchmark for evaluating slope stability was SF ≥ 1.5. Methods An assessment of the stability of the slope was conducted under three conditions: its original state, after reinforcement with gabions, and after the integration of gabions with mini piles. The dimensions of the gabion setting, as determined by the L-W-H notation (length-width- height), were 2 m x 1m x 0.5 m and 1 m x 2 m x 0.5 m. The pile was designed to be 2.5 m long at the gabion's end. The analysis was conducted at 45°, 60°, 70°, and 90° slopes. Results Based on the results of slope stability calculations, an SF = 1.11 was determined under no reinforcement conditions. By applying reinforced gabion walls measuring 2 m in width combined with mini piles at a 45° slope, the best SF was achieved, which was 2.58. Conclusion Given the comparable topographical circumstances, it is expected that the outcomes of this analysis on slope stability will be applicable in mitigating the occurrence of landslides.

Floor Heave Control in Gob-Side Entry Retaining by Pillarless Coal Mining with Anti-Shear Pile Technology

The severe floor heave in gob-side entry retaining is the major restriction factor of the wide application of pillarless mining thin coal seams. Reinforcement and stress-relief floor heave control methods are the most promising. However, in practice, floor restoration is widely used. Therefore, floor heave control technology in gob-side entry retaining needs to be improved. This study proposes anti-shear pile technology to control floor heave in gob-side entry retaining. The research was mainly carried out by numerical simulation. It was found that the transformation of high vertical stresses in the entry floor underneath the filling wall and coal seam body into horizontal stresses starts the floor heave process. The vertical dilatancy of rocks under the roadway span and their subsequent unloading lead to the delamination of the floor strata and uplift of the entry contour. In this paper, the best pile installation scheme was found. It is a 2pile 5+2 scheme with the installation of two piles, each 2 m long. After that, it was shown that filling piles are more than 3.3 times cheaper than comparable analogs, and pile installation is less labor-intensive. The implementation of the proposed floor heave control method leads to a reduction in heaving by 2.47 times.

The optimal operation decision of gas station considering charging pile installation – conflict and coordination

The optimal operation decision of gas station considering charging pile installation – conflict and coordination

Theoretical Analysis of Drilling Unloading and Pile-Side Soil Pressure Recovery of Nonsqueezing Pipe Piles Installed in K0-Consolidated Soils

Drilling with prestressed concrete (DPC) pipe pile is a nonsqueezing pile sinking technology, employing drilling, simultaneous pile sinking, a pipe pile protection wall, and pile side grouting. The unloading induced by drilling, the pipe pile supporting effect, and the dissipation of the negative excess pore-water pressure after pile sinking, all of which have significant effects on the recovery of soil pressure on the pile side, are the main concerns of this study, which aim to establish a method to reasonably evaluate the timing selection of pile side grouting. The theoretical solutions for characterizing the unloading and dissipation of the negative excess pore-water pressure are presented based on the cylindrical cavity contraction model and the separated variable method. By inverse-analyzing the measured initial pore pressure change data from borehole unloading, initial soil pressures on the pile side of each soil layer are determined using the presented theoretical solutions. Then, the presented theoretical solutions were verified through a comparative analysis with the corresponding measured results. Moreover, by introducing time-dependent coefficients αt1 and αt2 to characterize the pore pressure dissipation and rheology effects, the effects of the negative excess pore-water pressure dissipation on the pile-side soil pressure recovery are discussed in detail.

Enhanced multi-task learning models for pile drivability prediction: Leveraging metaheuristic algorithms and statistical evaluation

As a crucial component in construction, piles find extensive use in transportation infrastructure. Drivability, a term commonly employed to gauge the ease of pile installation, encompasses various factors. To evaluate the drivability, various indexes, such as MCS (maximum compressive stresses), MTS (maximum tensile stresses) and BPF (blow per foot) are proposed. Despite the need for multiple indexes to evaluate pile drivability, these metrics often share underlying commonalities, as they collectively describe features of the hammer-pile-soil system comprehensively. Thus, leveraging multi-task learning techniques becomes advantageous for tackling the drivability prediction problem. This paper proposes two enhanced multi-task learning models improved from MLS-SVR (Multi-output least-squares support vector regression machines) and hybridized with metaheuristic algorithms. Based on 4072 pile installing samples, the models undergo development and hyperparameter optimization employing SA (Simulated Annealing) and YYPO (Yin-Yang-pair Optimization). Six statistical indexes are employed evaluate the accuracy of the models. The test results reveal the superiority of YYPO-MLS-SVR over SA-MLS-SVR. Furthermore, comparative analysis against single-task models from previous studies demonstrates the robust performance of hybridized MLS-SVR models, even when addressing multiple problems concurrently. This paper presents a novel approach for the multi-index evaluation of pile drivability.