Load-settlement Behavior Research Articles

Bibliometric analysis of stone column research trends: A Web of Science perspective

Abstract Stone columns have garnered significant interest in geotechnical engineering as an effective ground improvement technique for enhancing the load-bearing capacity and mitigating settlement issues in soft soils. This study presents a comprehensive bibliometric analysis of scholarly literature on stone columns, utilizing data from the Web of Science database spanning from 1975 to 2023. The analysis aims to provide insights into publication trends, influential journals, key research institutions and authors, geographical distributions, and emerging themes in this domain. Through a systematic data curation process, 505 relevant publications were analyzed using Excel and VOSviewer software. The findings reveal a notable emphasis on geosynthetic encasements, load-settlement behavior, and soft soil reinforcement, with China being a major contributor. Over the past 48 years, the research has evolved from static loading to dynamic loading, sustainable structures, and artificial intelligence applications, as evidenced by the highly cited publications. This study maps the development, current state, and potential future directions of stone column research, serving as a valuable resource for researchers and practitioners in geotechnical engineering.

New Design Criteria for Long, Large-Diameter Bored Piles in Near-Shore Interbedded Geomaterials: Insights from Static and Dynamic Test Analysis

This paper presents an analysis of long, large-diameter bored piles’ behavior under static and dynamic load tests for a megaproject located in El Alamein, on the northern shoreline of Egypt. Site investigations depict an abundance of limestone fragments and weak argillaceous limestone interlaid with gravelly, silty sands and silty, gravelly clay layers. These layers are classified as intermediate geomaterials, IGMs, and soil layers. The project consists of high-rise buildings founded on long bored piles of 1200 mm and 800 mm in diameter. Forty-four (44) static and dynamic compression load tests were performed in this study. During the pile testing, it was recognized that the pile load–settlement behavior is very conservative. Settlement did not exceed 1.6% of the pile diameter at twice the design load. This indicates that the available design manual does not provide reasonable parameters for IGM layers. The study was performed to investigate the efficiency of different approaches for determining the design load of bored piles in IGMs. These approaches are statistical, predictions from static pile load tests, numerical, and dynamic wave analysis via a case pile wave analysis program, CAPWAP, a method that calculates friction stresses along the pile shaft. The predicted ultimate capacities range from 5.5 to 10.0 times the pile design capacity. Settlement analysis indicates that the large-diameter pile behaves as a friction pile. The dynamic pile load test results were calibrated relative to the static pile load test. The dynamic load test could be used to validate the pile capacity. Settlement from the dynamic load test has been shown to be about 25% higher than that from the static load test. This can be attributed to the possible development of high pore water pressure in cohesive IGMs. The case study analysis and the parametric study indicate that AASHTO LRFD is conservative in estimating skin friction, tip, and load test resistance factors in IGMs. A new load–settlement response equation for 600 mm to 2000 mm diameter piles and new recommendations for resistance factors φqp, φqs, and φload were proposed to be 0.65, 0.70, and 0.80, respectively.

Evaluation of load-settlement behavior of shallow footings using hybrid MLP-evolutionary AI approach with ER-WCA optimization

Evaluation of load-settlement behavior of shallow footings using hybrid MLP-evolutionary AI approach with ER-WCA optimization

Bayesian Back Analysis of Axially Loaded Pile Response Using Fibre Optic Strain Data

The load-transfer method has been extensively used to evaluate the deformation behavior of foundation piles, with the nonlinear load-settlement behavior of a pile-soil system modeled using load-transfer curves. Although load-transfer models have a considerable impact on the pile response, the model parameters are usually estimated empirically from soil parameters using transformation models, and the associated uncertainties are often neglected. Fiber optic sensing technology provides detailed axial strain information along the entire length of a pile; however, the full potential of such utilization has not yet been realized. This paper presents a Bayesian back analysis method for statistical descriptions of load-transfer curves and pile responses based on fiber optic measurement. A pile test case study is used to illustrate the proposed method, and several candidate model configurations are compared. The results show that the predicted pile response generally matches the measured data, and the quantified uncertainty allows for a better understanding of the possible ranges of the pile response, in addition to the single best-estimate result.

Load-Settlement Analysis of Axially Loaded Piles in Unsaturated Soils

Unsaturated soil covers a significant part of the world, and studying the behavior of deep foundations in this medium is an important step in increasing accuracy and economic efficiency in geotechnical studies. This paper presents an analytical solution to investigate the load-carrying characteristics of single piles embedded in unsaturated soils, accounting for the effect of groundwater level on the pile’s response. For this purpose, relationships for shear modulus and Poisson’s ratio for unsaturated soils were collected from the literature to consider their effects as key parameters on pile performance. A parametric study was conducted to evaluate the effect of soil moisture content on the behavior of the pile-soil system for different soil types, and the effect of pile slenderness on its load-settlement behavior was studied for varying soil moisture contents. The results indicate that the pile stiffness increases as the soil suction increases while below a critical slenderness value, hence increasing the pile load capacity. However, this improvement occurs within a limited range of soil suction that is narrower for coarse-grained soils. The pile settlement corresponding to soil failure was also evaluated by modifying the existing solutions for unsaturated soils. The developed solutions were verified against the predictions of published solutions as well as the results of finite element analysis and pile load tests. It was found that the system stiffness decreases by 50% when the water table rises from the pile toe level to the ground surface in the studied soil.

Model tests on ordinary and geosynthetic encased stone columns with recycled aggregates as filler material

PurposeSincethe availability of natural aggregates is very sparse, recycled industrial and construction waste provides a sustainable alternative to ground improvement using vibro replacement method. Utilizing recycled building waste caters the requirement for its disposal and offers an effective remedy for the scarcity of natural resources. The aim of this study was to give a sustainable alternative for the natural aggregates as the material for stone column.Materials and methodsA good stone column material should be hard, dense, chemically inert and must comply with the size requirement. The utilization of construction debris and spent railway ballast as column material has been the subject of numerous researches. This work focuses on finding the suitability of railway ballast and concrete debris as alternatives for stone column material. A detailed laboratory testing of these materials has been carried to judge their strength requirements as the material for both Ordinary Stone Columns (OSCs) and Geosynthetic Encased Stone Columns (GESCs). The improvement in capacity of both OSCs and GESCs is evaluated by performing California Bearing Ratio (CBR) test in laboratory by creating unit cell stone column models of different recycled aggregates and comparing their load settlement behavior with natural aggregates.Results and discussionRailway ballast, natural aggregates, concrete debris and virgin soil were found to show decreasing order in CBR test results. Loading required for causing settlement in both OSCs and GESCsshowed remarkable increase as compared to that of virgin clay and the maximum load settlement improvement was observed for railway ballast in both the types of stone columns. The CBR values for GESC made from railway ballast, natural aggregates and concrete debris were 54, 49 and 38% respectively. On the other hand, CBR for OSC made from railway ballast, concrete debris and natural aggregates were found to be 25.5, 20.4 and 24% respectively and CBR of virgin clay was found to be just 11%.ConclusionThe demonstrated application of sustainable sources in place of natural aggregates provides a crucial pathway for utilizing the recycled aggregates as stone column filler material. Up on encasing the OSC with geotextile the performance of stone columns has improved appreciably in terms of load capacity. Railway ballast and concrete debris can be adopted as an alternate for the natural stone column materials to improve the bearing capacity of site consisting mainly of soft clays.

Machine Learning Models to Evaluate the Load-Settlement Behavior of Piles from Cone Penetration Test Data

Machine Learning Models to Evaluate the Load-Settlement Behavior of Piles from Cone Penetration Test Data

Using shear modulus to predict the bearing capacity of strip foundations on sand

This paper reports results of a study to predict load-settlement behaviour of strip foundations on a dry uncemented sand using only soil stiffness data, under both working loads and extreme loads. This involved predicting the strength of a foundation system without using any strength parameters. A non-linear stepwise load-settlement prediction algorithm was utilised, which used the small-strain shear modulus of layers below the footing, a suitable stiffness modulus reduction curve and elasticity theory. The algorithm was adapted to predict the ultimate bearing capacity, as well as to construct astress-settlement curve and determine the bearing pressure experienced beneath a foundation at any particular settlement. The method was evaluated using two different sets of modulus reduction curves, for small-scale model foundations on loose, medium dense and dense sand. Model tests were conducted at 1g. Particle Image Velocimetry (PIV) was used to observe strains within the soil during loading. These strains were used to calculate the shear modulus of discrete layers throughout loading and back-estimate the layer small-strain shear moduli. Additionally, the mode of shear failure for each test at ultimate bearing capacity was observed using PIV. Modulus reduction curves that initially degrade shear modulus rapidly beyond the elastic threshold strain (0.001%) gave superior predictions under the given conditions. Using such curves, ultimate bearing capacity predictions produced errors of 0.4% to 10.8%. Using the same input parameters, stresssettlement predictions were of satisfactory accuracy over the entire settlement range.

Numerical Study of Inverted Shell Footing Behavior on Sandy Soil

Inverted and upright shell foundations, are increasingly utilized in engineering projects as structural elements beneath buildings, towers, curved dams, and other structures. They serve as economical alternatives to shallow foundations when encountering high loads transmitted through weak soil. The purpose of this research is to use the numerical modeling program Midas GTS NX to better understand the load-settlement behavior of inverted shell footings subjected to vertically applied loads. The study involved variables related to the properties of shell cross-sections, embedment depth of footing, and angle of side slope of footing. Also, the shell efficiency factor and the non-dimensional settlement factor for the shell footing are studied. The results show that inverted shell footings exhibit higher load-carrying capacity compared to traditional flat footings. Furthermore, it was found that inverted shell footings within the range of side slope angles of 15°–30° have a higher load-carrying capacity than traditional flat footings. Additionally, an increase in embedment depth was shown to be effective in enhancing the load-carrying capacity of inverted shell footings. From the obtained results, it was also concluded that the shell efficiency factor (η) of inverted shell footings is high. In particular, the inverted pyramid shell footing with an angle of 15°–30° exhibited higher efficiency compared to other footings, by 48.3% and 39.8%, respectively. The settlement improvement factor (Fa) of inverted shell footings was found to be low with the inverted pyramid shell footing at an angle of 15°–30° having a lower value compared to others by 5x10-4 and 507x10-4, respectively.

Soil plug behaviour of open-ended model piles jacked in cohesionless soil

ABSTRACT The objective of this study is to investigate the behaviour of soil plugging of open-ended pipe piles under various soil and pile conditions. Extensive laboratory tests were conducted on small-scale model pipe piles installed in sand with varying soil conditions. The diameter of the pile, soil density, rate of penetration and the degree of saturation all influenced the soil plugging behaviour. The laboratory test results indicated that the length of the soil plug typically increases as the diameter of the pile increases and the relative density of the soil decreases. Additionally, the plug length decreases as the matric suction value increases. The jacking force was found highly dependent on the plugged length and particle properties of the soil. The effect of penetration speed on soil plugging and load settlement behaviour were also investigated. Finally, a correlation has been developed between the plug length ratio (PLR) and the incremental filling ratio (IFR).

A rigorous analytical approach to predicting the load–settlement behavior of axially loaded piles embedded in sands incorporating the SANISAND model

A rigorous analytical approach to predicting the load–settlement behavior of axially loaded piles embedded in sands incorporating the SANISAND model

Finite Element Analysis on Load-Settlement Behavior of Axially Loaded Pile on Sand

The analysis of geoengineering problems using various constitutive models necessitates substantial field and laboratory research, which entails a significant investment of time and money. As a result, the application of Finite Element Analysis in geoengineering projects is limited. This research focuses on numerically examining the behavior of a pile in a sandy soil layer. The study employs different relationships to estimate soil parameters from standard penetration tests and simple lab tests. These derived parameters, required for the Mohr-Coulomb & Hardening Soil constitutive model and the linear elastic model of the pile, are implemented in the PLAXIS 3D software. This software is used to simulate the settlement of the pile in sandy soil incorporating factors like mesh density and soil-pile interaction. The results of the study reveal that employing a finer mesh size leads to more precise results. Additionally, an interface strength of 67% proves to be more accurate for this study. Furthermore, the correlation introduced by Papadopoulos (1982) exhibits a close relation with field settlement values. In contrast, other correlations either overestimate or underestimate the results. Moreover, the study conclude that Mohr-Coulomb constitutive model satisfactorily predicts the behavior of the pile for the study area.

Effect of eccentric loads on the behavior of circular footing with/without skirts resting on sand soil

The stability of circular footings under eccentric vertical loads is a significant problem in geotechnical engineering. Therefore, this paper shows the results of experimental tests carried out on an eccentrically loaded circular foundation on sand soil. The focus of this research is on examining how eccentric loads affect the behavior of circular footings on sand soil, both with and without skirts. Various load eccentricities (e) equals zero, 2.50, 5.00, 7.50, 10.00, 12.50, 15.00, 17.50 and 20.00 mm are used. In addition to, a 60 mm-diameter circular foundation and sand with an 85% relative density (Dr) are used in this experimental study. To study the effect of changing the skirts depth on the load-settlement response skirts with different depths (h) = 60 mm, 150 mm, 240 mm are used for vertical reinforcement. In comparison to the unreinforced condition, test findings show an improvement in ultimate bearing capacity. When the skirts are positioned at the ideal embedment depth L/D = 4, it is found that the circular footing's load-settlement behavior is enhanced by 92% and 93% in case of using (e/D) ratio = 0.125 and 0.25 compared to the unreinforced case.

Estimation of internal friction angle for working platform materials by plate load test

This paper reviews the load–settlement behaviour of 499 plate load tests of various diameters undertaken on granular soils and working platform materials to determine the angle of internal friction mobilised by the test. The observed settlement of individual plate load tests at relatively small settlement has been extrapolated to a theoretical failure of the plate at 10% and 15% of the plate's diameter (D). For each test an effective angle of internal shearing resistance was calculated based on the bearing resistance associated with the stress required to cause settlement of 0.10 or 0.15 times the plate diameter. The results are presented along with a discussion on the use of high-friction materials in working platforms and shallow foundations. Characteristic values for the effective angle of internal shearing resistance are provided for all working platform materials tested, as well as tests undertaken on platform materials comprising crushed brick and concrete. These values are compared to shear box test results on similar materials. Characteristic values of ϕ′ varying from 44° to 46.4° (0.1D) and 45.3° to 47.8° (0.15D) for crushed brick and concrete materials are calculated, which are slightly higher than those determined from tests on Type 1 material.

Numerical Analysis on the Behavior of Floating Geogrid-Encased Stone Column Improved Foundation

The ordinary (OSC) and geosynthetic-encased stone column (ESC) with different bearing strata significantly influenced its behavior. The paper established seven models for studying the behavior of floating stone columns using the finite difference method (FDM). The effect of geogrid and column length on the load-settlement behavior, bulging deformation, failure mode, and load transfer coefficient were also analyzed based on proposal models. The results showed that the bearing capacity of F-OSCs and F-ESCs increased with the increase in column and encasement length, respectively, and a critical length (i.e., 4D, where D was the column diameter) was found in settlement improvement. The bulging deformation was significant in F-OSCs and was observed at the top of a long column and the full length of a short column. The geogrid encasement could constrain the OSC to decrease the bulging deformation. The failure mode in F-OSCs was mainly a punching failure with bulging deformation for a short column (e.g., less than 4D), and was relative to the vertical pressure for a long column. The failure mode in F-ESCs was a punching failure, and the punching degree increased with an increase in encasement length. The load transfer coefficient of F-OSCs or F-ESCs was relatively stable as the column length increased to a critical value (e.g., 4D) or the encasement length increased to a critical value (e.g., 4D).

Load–Settlement Behavior of Coconut Midrib Strip Geogrid Reinforced Granular Soil

Load–Settlement Behavior of Coconut Midrib Strip Geogrid Reinforced Granular Soil

Numerical Analysis of Single Stepped Axially Loaded Pile

Abstract: This study investigates the behavior of a single pile under axial loading in granular soil layers. The study aims to determine the impact of stepping on load settlement behavior and load transformation along the pile, as it relates to depth. The pile has a diameter (D) of 1m and a length (L) of 20m. For the stepped pile, the upper portion is half the length of the pile and the lower portion is the remaining half. The total length and volume of the pile are kept constant for both the single conventional pile and single stepped pile. In the analysis, the diameter of the upper portion of the stepped pile is reduced (stepped pile) by 0.1D to 0.3D, and the diameter of the lower portion is calculated accordingly. Also the load transformation with respect to depth of pile is studied. Based on numerical analysis, the single stepped pile outperforms the single conventional pile in load settlement behavior.

Investigation of the Load-settlement Behavior of Box-shaped Deep Foundations

The load-settlement and monolithic behaviors of a new type of deep foundation in sand named Box-Shaped Deep Foundation (BSDF) were studied, and a comparison to Conventional Piled Raft Foundations (CPRF) was made by carrying out extensive numerical analysis. Physical model tests were also conducted to validate the numerical approach presented in this study, and it turned out to be a reasonable agreement. In the scope of this paper, the results of the parametric study are presented, and design strategies for an optimized design of BSDFs are discussed.

Experimental and Numerical Analysis of Piled Raft Foundation with Different Length of Piles Under Static Loads

In order to understand the effect of (length of pile / diameter of pile) ratio on the load carrying capacity and settlement reduction behavior of piled raft resting on loose sand, laboratory model tests were conducted on small-scale models. The parameters studied were the effect of pile length and the number of piles. The load settlement behavior obtained from the tests has been validated by using 3-D finite element in ABAQUS program, was adopted to understand the load carrying response of piled raft and settlement reduction. The results of experimental work show that the increase in (Lp/dp) ratio led to increase in load carrying capacity by piled raft from (19.75 to 29.35%), (14.18 to 28.87%) and (0 to 16.49%) , the maximum load carried by piles decrease from(9.1 to 22.72%), (15.79 to 47.37%) and (44 to 81.05%) and the response of settlement piled raftdecrease from (16.67 to 23.33%), (9.09 to 39.39%) and (30%) with increase the number of piles from 4 to (6 and 9) and (length of pile / diameter of pile) ratio increase to (14.14 and 21.2), respectively. The numerical and model test results are found to be in a good agreement.

Experimental evaluation of heave characteristics in sand bed reinforced with closely woven rattan mats

The restrictions imposed on infrastructural development in a country due to the scarcity of structurally sound and stable earthen base can be resolved by means of suitable ground improvement methods. Soil reinforcement using natural fibers like coir, jute, sisal and bamboo have attracted our recent attention due to the achievement of promising results in the field of geotechnical engineering. The present study investigates the potential benefits of using rattan for reinforcing sand beds as an alternative to geosynthetic products. Rattan being an eco-friendly and easily available material has been decided to be used in the form of rattan strips to fabricate closely woven rattan mats. Series of plate load tests were carried out to study the load settlement behavior of square model footing resting on sand bed reinforced with closely woven rattan mats. The paper presents the results obtained after varying the parameters like top layer spacing, number of reinforcement layers and width of reinforcement. A considerable reduction in heave was observed after placing rattan mats of width 3B at an optimum spacing of 0.3B. The experimental investigations indicates that the heave has reduced to 97 % after incorporating four layers of planar rattan mats at optimum spacings when compared to unreinforced sand.