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Because of the deltaic nature of the Netherlands, deep soft soil deposits are widespread. Due to the population density exploitation of underground space is vital for commercial developments and transport networks. Piles are used as primary support elements in deep excavations, cut and cover tunnels, quay walls, flood defences and to provide uplift resistance to the base of tunnels and basements. This paper examines empirical correlations linking the Cone Penetration Test (CPT) end resistance qc and the resistance of deep foundations in sand. It is found that correlations between qc and pile end resistance are independent of pile diameter. However, the impact of installation method, residual load, plugging and sand creep should be considered. In the case of shaft resistance, constant correlation factors between qc and average shaft resistance are possible for non-displacement piles. For the case of displacement piles, correlations that include the effects of friction fatigue and pile plugging during installation are recommended.

The new railway bridge over the Nosická dam is a part of the complex modernization of the railway corridor from Púchov to Žilina. Our company participated on the project using a wide variety of special foundation techniques on artificial islands for piers P6, P5, P4 and P3 and the pillar foundations. We applied the many years of experience gained by our company through working on projects involving water. Bored piles, as well as vibrated sheet piles, welding and assemblage work have all been carried out from a floating pontoon platform and also there was jet grouting applied to stabilize embankments. At the same time we provided active assistance with temporary floating bridges and platforms for the kind of transfer on water required by our client.

Kula Belgrade is the tallest building within Belgrade Waterfront project, located at the right bank of the Sava river. It is envisaged as the future landmark of Belgrade and pivotal point of Belgrade Waterfront development. It consists of 168m high - 42 storey tower, podium and eccentric basement. It is one of the rare towers in the world in which the bottom and the top parts are mutually rotated by 90° in plan and where such transition is achieved through 7 floors. Such configuration imposed significant demands to structure. The paper addresses design of structure, which has been divided in two stages - piles and structure above the piles. Former was provided by SOM company from Chicago, USA; latter by AECOM company from UAE, both as per American International Building Code. DNEC company from Belgrade was a member of Joint Venture of local companies in charge for nostrification of design and permitting process. Check of design was conducted per Eurocodes. During the construction stage, DNEC was in role of Engineer but was also actively involved in structural value engineering process in which the composite structural members (reinforced concrete with embedded steel) of transition zone were converted to reinforced concrete or post-tensioned members. Link beams of main core that comprised embedded steel plates were redesigned as RC beams, but due to the openings in web their adequacy was checked by non-linear analysis in Abaqus software.

The main objective of this work is to present an innovative method of numerical modeling of anchored piles system acting as a road protection against landslide, called the “2D/3D method”. Firstly, short description of the problem and “state of the art” review are included. An effective methodology of the design supported by the numerical analysis, solving the problem of interaction of a periodic system of piles and the unstable soil mass is presented, for which some detailed information about proposed numerical approach is given. The key idea of 2D/3D method is to join the pile with the 2D plane strain continuum by fictitious connectors of Winkler type with P-Y properties identified during the analysis of a subsidiary 3D problem. Practical example of usage of proposed approach to a real case of a road endangered by a landslide then protected by the piles system is presented. On the base of this example, a discussion about important design issues like internal forces in piles (mainly bending moments) and anchors (tensile forces) or overall stability of the soil-structure system is done.

Aims. The purpose of this work is to justify the reliability of the developed models of pile foundations on the data of field observers and to demonstrate the feasibility of using pile foundations to increase the stability and bearing capacity of the NPP structures foundation using the example of reactor building (RB). Methods. The data of field observers for the settlement of the RB are presented. The expressions for calculation of the static stiffness of the contact surface of the slab bottom and soil medium, as well as for pile foundations taking into account the effects of interaction of grillage and pile field with the soil media with a general character of displacement of a circular cross section pile are submitted. A spatial three-dimensional finite element static model of RB was developed together with the soil base. Isolines of vertical movements of RB fundamental slabs for natural foundations, as well as for pile foundations for normal operation are shown. A comparative analysis of the data of field observers with the calculation results allows us to justify the reliability of the developed model of the pile foundation. Results. The calculations of the foundation yield correspond to all the period of operation including construction, and the results of observations relate only to the period of operation that explain the difference. A comparative analysis of the data of field observers with the calculation results allows us to justify of the strong effectiveness of realization of pile foundation for the massive structures on soft soil bases.

Analysis of the applicability of wave model solution to evaluate the variation of the dynamic stiffness in the pile foundation versus the distance between piles at the vertical vibrations; both experimental data from references and our own measurements in field are involved. To justify the reliability of the solutions of the wave models used to determine the dynamic stiffness values of the pile foundations at the vertical vibrations, we use the data obtained experimentally for the determination of natural frequencies in the cap-bound groups. The data obtained for the natural frequencies of 3×3 floating piles with different distances between them are considered. In addition, the data found at the forced vertical vibrations of the cap-bound groups of 2×2 piles under different loads and at different distances between the piles are involved. Processing of available amplitude-frequency curves involves the solution of the inverse problem with the theory of nonlinear vibrations to determine the parameters of the “pile group – soil” system, namely the effective mass, stiffness, and damping. The correlation between the measured and predicted data is evaluated by using the data obtained at the description of the pile groups in soil behavior. It has been found that the relations obtained at the solution of wave models and used to calculate the dynamic stiffness at the vertical vibrations of pile foundations consider the mutual effect of the piles in the group and permit satisfactory accuracy of the results. The maximum discrepancy between the results and experimental data is 15 %.

This paper studies the effect of loading eccentricity and pile spacing on the ultimate lateral soil resistance of twin-piles using finite element limit analysis and analytical upper bound plasticity methods. Two kinematic mechanisms corresponding to the failure modes produced by the advanced finite element simulations are postulated with different eccentricity and pile spacing cases. Comparisons have shown excellent agreements between the two approaches. A series of parametric studies are then subsequently performed. Numerical results have shown that loading eccentricity considerably affects ultimate lateral soil resistance, leading to a maximum reduction of 50%. In addition, the curve of normalised pile resistance versus pile spacing ratio is dissimilar to that without considering the effect of loading eccentricity. The proposed solutions and failure mechanisms in this study will provide a deepened insight on the performance of twin-pile group under eccentric loads.

Root piles are injected and installed during mortar shaft construction, using pressures of up to 500 kPa. The executive control is typically done through static load testing, an expensive and time-consuming method. Static load tests on eight controlled piles (diameters between 310 mm and 410 mm) were performed, aiming at evaluating pile ultimate load. This study suggests an innovative, non-destructive approach to validate root pile field performance, using a digital speedometer connected to the drilling rig’s rotating head. The proposed method monitors variables related to bearing capacity during pile installation and proposes an empirical equation to estimate the ultimate bearing capacity of root piles. For the assessed piles, the predictions obtained with the proposed equations agreed fairly well with results from static load tests, proving it as a feasible and helpful option for the executive control of root piles, especially when load tests are not available.

Root piles are injected and installed during mortar shaft construction, using pressures of up to 500 kPa. The executive control is typically done through static load testing, an expensive and time-consuming method. Static load tests on eight controlled piles (diameters between 310 mm and 410 mm) were performed, aiming at evaluating pile ultimate load. This study suggests an innovative, non-destructive approach to validate root pile field performance, using a digital speedometer connected to the drilling rig's rotating head. The proposed method monitors variables related to bearing capacity during pile installation and proposes an empirical equation to estimate the ultimate bearing capacity of root piles. For the assessed piles, the predictions obtained with the proposed equations agreed fairly well with results from static load tests, proving it as a feasible and helpful option for the executive control of root piles, especially when load tests are not available. [ABSTRACT FROM AUTHOR]

In this paper, two types of bridges were taken to carry out the analysis and design according to the AASHTO Code and the SAP2000 program, in the beginning, work is done using AASHTO Code and both bridges are designed and analyzed, the first one was the suspension bridge and the second was a bridge supported in the pier region only. The two models, 16 piles with a diameter of 3.8 m were carried out on each pier. After that, the two models are analyzed and designed according to the SAP2000 program to calculate moment, shear and deflection for both bridges. So that the two models are compared based on torque, shear, impact loads and deflection to find out which one of the two models is more suitable for use in a long girder span. The comparison between the AASHTO Code and the SAP2000 program is also made based on the loading to show its effect on the stability design. The AASHTO code and the SAP2000 program are the most appropriate when analyzing and designing for two models. There is a slight difference in moment where the proportions were approximately (6-9)%. As for shear for both methods, the values for the suspension bridge were greater than those of the supported bridge. The difference was about (27-26)%. [ABSTRACT FROM AUTHOR]

The roughness elements are efficient tools to control the features of the hydraulic jump in the rectangular stilling basins. The present study suggests the use of modified elements to control the features of the free jump. The proposed tool is an incomplete circular pile. The use of piles in a one row with the different setup has been investigated. The measurements showed that the case of piles with the comparative summation areas A/∆=6.72 and the comparative distances between piles X/H1 =0.0 reduced the comparative height and length of the free jump by 11% and 24.6%, respectively. The paper detected the necessary helpful statistical formulas for the phenomenon.

At some coastal areas in Egypt, especially Port Said and Damietta, there are layers of loose to medium silty sand with traces of seashells fragments at the surface, overlying a very deep soft clay layer. The construction of shallow foundations over such soil formation is difficult and in some cases is not possible due to the high soil compressibility, large settlements, low bearing capacity, and near surface groundwater. In such case, small diameter piles could be used especially under low rise structures to transmit the structure loads with much lower settlements. A finite element-based numerical analysis using ADINA software (Version 9.4.2) ‎[4] is used to analyze and study the behavior of piles in such soil formations. Results indicated that both pile diameter and embedded length in loose sand have significant effect on the pile capacity and settlement on the other hand pile embedded length in soft clay layer has no effect on either pile capacity or pile settlement. One of the key findings of this study is that, most of the load carried by the pile transmitted to soil by skin friction so that, the choice of using pile foundation in such soil formations is practical to some extent.

Abstract Low strain integrity tests in piles are relatively cheap, of quick execution and nondestructive. Despite all these advantages, several variables are involved and the influence of external factors can complicate the interpretation of the results. Between them, the influence of the pile reinforcement can be high lighted. In piles partially reinforced, the difference in density and elastic modulus of the concrete in different parts of the pile and the influence of the process of introducing the reinforcement bars can induce some reflections in the test that can be confused with damage in the pile and, therefore, should be taken into account to analyze the tests results. In this research, the influence of the reinforcement embedded in the piles is analyzed using numerical (FEM) simulations and comparing them with tests made in the field. A new classification of possible damages is proposed based on the analysis of the reflections observed at the end of the reinforcement cage embedded in a pile partially reinforced.

Abstract The steel-concrete composite sections are often used in civil building in Brazil and around the world. The connection of the steel profile and the concrete slab increases the performance of the composite structural element due to the use of the advantages of each material. In this article, a bar element is used with an interface element for nonlinear analysis of steel-concrete composite beams with partial interaction. The objective is to develop an algorithm that uses this analysis tool to design steel-concrete composite beams looking for project optimized in terms of material costs. Defined spans, supports, ultimate and service load, an optimization algorithm is used to define the dimensions of the rectangular cross section of the concrete slab, I-shaped steel profile, and the reinforcement bars of the concrete slab, so that the quantity of these materials are the minimum to ensure structural safety, considering the ultimate and service limit states. The design constraints are obtained from building code requirements for concrete, steel and composite structures. The objective function is defined as the cost per unit length of the composite beam, obtained from the unit cost of each material, steel, concrete and reinforcement. In the optimization process, the iterative method sequential linear programming is used, in which the nonlinear problem is approximated by a sequence of linear problems, which has its optimum point defined step by step by the Simplex method. Examples of composite beams with ultimate loads defined in the literature were used to validate the implementations. Other examples were analyzed, being evaluated at each iteration the restrictions and objective function to verify the efficiency of the algorithm.

Objective The present study aimed to assess and compare the surgical outcomes of hemorrhoidectomies performed using two different techniques: conventional Milligan-Morgan and another popular vessel sealing approach of LigaSure hemorrhoidectomy. Methods This retrospective study was conducted at our tertiary care hospital and involved patients who underwent either of the surgical procedures from June 2016 to March 2022. The patient demographics and data on the duration of operation, hospital stay, and postoperative recovery were collected and evaluated. Results Of the 91 cases reviewed, a total of 44 patients underwent Milligan-Morgan open hemorrhoidectomy and 47 had LigaSure hemorrhoidectomy. The mean operative time was significantly shorter for LigaSure hemorrhoidectomy (33.84 ±9.18 vs. 23.15 ±3.36 minutes for Milligan-Morgan and LigaSure, respectively, p<0.0001). Additionally, in comparison to Milligan-Morgan open hemorrhoidectomy, the LigaSure hemorrhoidectomy group exhibited a significant reduction in hospital stay (2.20 ±0.79 vs. 1.47 ±0.50 days), lower pain score [6.55 ±1.19 vs. 5.30 ±1.10 on the visual analog scale (VAS) on day one and 2.25 ±1.26 vs. 1.47 ±0.78 VAS on day seven], and faster return to normal activities (18.18 ±4.30 vs. 14.85 ±3.15 days). Conclusions When pitted against the traditional Milligan-Morgan method, the LigaSure approach to performing a hemorrhoidectomy is superior, owing to the shorter duration of operation, shorter hospital stays, lesser pain, and earlier return to normal activities. In light of these findings, surgeons may consider choosing this procedure to improve surgical outcomes and efficiency., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Institutional Ethics Committee at Dayanand Medical College and Hospital (DMCH), Ludhiana issued approval IEC No: 2022-737. Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Virk et al.)

Background Hemorrhoids are an extremely common surgical condition affecting millions of individuals worldwide. Treatment options for hemorrhoids vary depending on the severity of symptoms and the type of hemorrhoids. The common non-surgical procedures for grade one and two hemorrhoids include rubber band ligation and sclerotherapy. The present study aims to compare the efficiency of rubber band ligation and sclerotherapy for the treatment of symptomatic grade one and two internal hemorrhoids in a tertiary care hospital. Methodology We conducted a one-year longitudinal survey among 200 patients with internal hemorrhoids in a tertiary care center in Madurai. We gathered data on demographic profiles, symptoms, postoperative complications, intraoperative pain, and treatment outcomes. Data analysis was done using the Pearson chi-square test to assess the difference between rubber band ligation and sclerotherapy treatment groups. A p-value <0.05 was considered statistically significant. Results A total of 200 patients were studied, of whom 100 belonged to the rubber band ligation treatment group and 100 belonged to the sclerotherapy treatment group. The preoperative symptoms were similarly distributed between both treatment groups. Intraoperative and immediate postoperative pain was higher in the rubber band ligation group than in the sclerotherapy group. Post-procedure complications were more commonly seen in the rubber band ligation group than in the sclerotherapy group at various weeks of the procedures. Conclusions Postoperative complications such as bleeding, prolapse, and infection/discharge were significantly different between the two treatment groups. The treatment outcome was significantly different between the two treatment groups after three, six, and nine weeks postoperatively. Overall, the sclerotherapy group was associated with fewer postoperative complications, more excellent patient response, and a more complete response to treatment than the rubber band ligation group., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Institutional Ethics Committee, Velammal Medical College Hospital and Research Institute issued approval VMCIEC/25/2021. Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, J et al.)

This paper presents a closed-form solution on the steady dynamic response of circular piles embedded in inhomogeneous soil. The soil is modeled as a viscoelastic continuum, and the pile is modeled as a one-dimensional elastic shaft. Fictitious soil pile model and Hamilton's energy principle are introduced to deduce the equations governing the layered pile–soil system. Impedance transfer method and iterative algorithm are deduced to decouple the pile–soil dynamic interaction. The results show that the modulus and thickness of inhomogeneous soil profile play a more significant role in the dynamic stiffness than the damping effects. The variation pattern of the dynamic impedance against the modulus of layered soil is dominated by the cut-off frequency. Particularly, in Gibson soil, the stiffer surface soil yields the greater pile-head stiffness. The dynamic stiffness of piles in Gibson soil could be approximated by two or more soil layers with equivalent Young's modulus. [ABSTRACT FROM AUTHOR]

The aim of this present paper is to provide lower bound bearing capacity factor Nc for axially loaded circular piles in clays by using two-dimensional finite elements and the three-dimensional non-linear Tresca yield criterion. The clay layer is assumed to be completely saturated and subjected to undrained loading. The edge discontinuities of the Tresca surface was smoothened by providing a C2 rounded surface at the vicinity of the sharp corners of the regular hexagon lying on the octahedral plane. No inherent assumption of hoop stress was considered in the present analysis. The clay has been considered to be heterogeneous where the cohesion increases linearly with depth. The study is useful in providing the methodology for simulating the axisymmetric structures and providing the design chart for the bearing capacity factors for circular piles in clays whose cohesion increases linearly with depth. [ABSTRACT FROM AUTHOR]

A probabilistic analysis approach for estimating the durability of piles with microcracks under chloride attack is presented. The chloride ingress model is obtained by considering the time-dependent diffusion process. The equivalent diffusion coefficient is derived to investigate the crack effect by introducing the crack effect factor. The fitting formula between the chloride diffusion coefficients and crack widths is established through experimental results, and the proposed equivalent diffusion coefficient is verified by comparison with the experimental results. The probabilistic evaluation of durability of piles with microcracks is performed, and then the parametric analysis is performed to study the effect of main parameters on the failure probability and durability life. The results indicate that the chloride concentration increases rapidly as the crack width increases at the same number of cracks. The durability life greatly reduces with increasing crack density of pile. The durability life predicted by probabilistic method is always less than those by deterministic method at the same condition. The deterministic approach may underestimate the threat of reinforcement corrosion induced by chloride attack, owing to the omission of probabilistic nature of main influencing parameters. [ABSTRACT FROM AUTHOR]

Herein, an experimental investigation of the plugging impact on the capacity of open-ended piles installed in clayey soil is presented. Model tests involving static axial compression load tests are carried out on four open-ended modeled piles with different diameters (12.5, 19, 25, and 50 mm). In the same manner, four closed-ended modeled piles are tested to make a comparison. A load cell system is used to determine the resistance acting on the piles, with an instrumented transducer on the outside walls of the pile. The eight steel model piles are tested in the circular steel tank with a diameter of 350 mm and 400 mm in length. Three undrained shear strengths of the clay sample, 5 KPa, 10 kPa, and 18 kPa, are used in model tests. The outcomes of the tested models uncover that the pipe pile capacity is mainly mobilized at the low shear strength. In addition, it is realized that the soil plugging in the small diameter has an impact on pipe pile capacity. Based on experimental results, five statistical models are established to achieve relations between the maximum load for the closed-ended pipe. It is realized that the value of Qexp is highly correlated with the diameter and Qcalc.. [ABSTRACT FROM AUTHOR]

Background: As there is controversy and disagreement with respect to treatment of Haemorrhoids adopted by conventional method due to inefficacy, relapse and complications are seen. It is most prevalent ailments and impacts the quality of life significantly. Haemorrhoids are enlarged, swollen veins around the anus externally or in lower rectum1. This study aim to access Role of Sulphur in Cases of Haemorrhoids as a constitutional2,3, medicine follow well2,3, anti miasmatic5,6. The Study showed near about 100% of cases responded to Sulphur4,5, thus proving effective role of Sulphur in Haemorrhoids. The study aim role of Sulphur in Haemorrhoids. A minimum of 1 year and 15 to 70 yrs of age and six matched controls were included in the study. As there is controversy and disagreement with respect to treatment of Hamorrhoids adopted by conventional method due to inefficacy relapse and complications are seen. It is most prevalent ailments and impacts the quality of life significantly. Haemorrhoids are enlarged, swollen veins around the anus externally or in lower rectum1. Material And Methods: Here patients were subjected on clinical presentation and examination using standard scales measuring severity and anoscopy. The entire process was done using standard case research record with a follow up of minimum 3 months period. Result: Out of 30 patients screened, it was observed that 66.6% of affected patient were in age group of 25-40, 16.7% in 41-54. Males prevalency was present and in that 26.6% were service class, driver 13.3% and mechanics 13.3%. Showing occupation played a significant role. The study should 100% of cases responded to sulphur as a constitutional medicine in 23.3% cases, as a follows well cases in 60%. Conclusion: Hence we conclude that along with Homoeopthic medication used as constitutional, follow well, Dietary corrections, correction of sedentary habits by exercise etc. Which are the predisposing factors is also mandatory. [ABSTRACT FROM AUTHOR]

The difficulties with the application of low strain integrity testing for evaluating the length of driven precast piles of two sections justify the need for new data acquisition and analysis techniques. The standard time domain analysis of the recorded signals may not allow for distinguishing the desired responses from a pile toe and a splice. In this paper, we propose the use of a set of hammers of different weights and tip materials that will provide various sensitivities of the test to a pile splice. To further analyze the collected data, we study the distributions of phase angles obtained using complex continuous wavelet transform. The characteristic phase shifts that distribute from higher to lower frequencies can be interpreted as responses from a pile toe and a splice. To verify the proposed approaches, a series of numerical simulations were performed using the finite element method for the driven pile models with the different properties of a splice zone. Numerical simulation results show that the pile splices are clearly identified when using the shorter input pulses which can be generated by light hammers with a hard head material. The total length of a simulated pile with a 1 mm air gap between sections was undetectable by standard data analysis approaches and was evaluated when analyzing the wavelet phase angle distributions. Numerically validated data acquisition and analysis techniques were applied to field data analysis and allowed us to confidently identify the length of two-section piles grouped with a pile cap.

Low strain integrity testing for pile quality control, based on the analysis of elastic waves, is one of the most common methods, due to its high efficiency. However, it also has a number of limitations that should be taken into account during pile testing. For additional study of the method and its effectiveness, an experimental site was constructed, consisting of ten cast-in-place piles with embedded defects. When analyzing field data, pile defects were not identified. For further analysis of the problem, as well as for interpreting the results and identifying pile defects, a cluster analysis method, the so-called ANN-classifier, is proposed. This paper describes the results of creating an algorithm for the recognition of defects and their localization in cast-in-place piles. It is proposed that use of the characteristic points of the spectrum of the signal as the input vector of the ANN classifier, and the type of pile defect as the output vector, is optimal. The results of the study led to the conclusion that the ANN-classifier can be used as the main tool for automatic interpretation of the results obtained by low strain integrity testing.

Firebrands are known to cause ignition of structures far from the primary fire front, resulting in significant damage to structures before firefighting can be attempted. To make structures more resilient to firebrand ignition, a better understanding of the heat transfer from firebrands to surfaces is needed. This paper provides a statistical assessment of different factors expected to have an impact on the heat flux from firebrand piles to a flat surface. The factors included in the study were wood moisture content, wood type (hardwood or softwood), wood density, wood state (live, dead, or artificial), wind speed, pile mass, firebrand diameter, and firebrand length. Using design of experiments, test matrices were developed that permitted a statistical analysis to be performed on the data. This statistical analysis was used to quantify which factors had a statistically significant impact on the heat flux from the pile as well as ranking the importance of the different factors. Artificial firebrands were found to have statistically higher heat fluxes compared with natural firebrands. Other factors that had a statistically significant impact on the heat flux were wind speed, firebrand length, and firebrand length-diameter interaction. Firebrand aspect ratio (related to the firebrand length-diameter interaction) is directly related to the pile porosity, which is a measure of the volume of air in the pile. Increasing the aspect ratio (which increases the pile porosity) results in higher heat fluxes across a larger region of the pile and was found to be an important factor. Firebrand diameter and pile mass were found to affect the burning duration but not as significantly as other parameters. The number of firebrands in the pile was also observed to potentially affect the heat flux, with a critical number required to reach the highest heat flux for a given firebrand geometry.

Static and dynamic behavior of above-ground steel storage oil tanks resting on end bearing piles or stone columns are studied and analyzed using ADINA (2019) program. The studied soil profile is an upper soft clay soil layer, followed by an extended dense sand layer. The main purpose of this research is to explore to what extent stone columns can be used as an effective alternative to concrete piles under steel storage tanks. Therefore, many three-dimensional numerical models are conducted to analyze and study the performance of such tanks in both static and dynamic cases. Ten of the studied cases are steel tanks resting over stone columns with different numbers and properties. On other hand, one model studied the behavior of steel tank resting on large diameter concrete piles. Results indicate that stone columns can be used instead of end bearing piles as long as the computed settlements are safe. In addition, stone columns are behaving better than concrete piles in decreasing of hoop stress in tank shell. It is also noticed that stone columns with high elastic modulus are effective in reducing the sloshing height of the oil surface during earthquakes. [ABSTRACT FROM AUTHOR]

Laboratory measurements were done of the end-bearing and side-shear stresses on small piles subjected to “static” and rapid load tests. Interpretation, by the unloading-point method, of the results of rapid tests were done to estimate what the behaviour under a static test would have been if it had been done instead. Comparisons were made of the estimated static test behaviour to the actual static test behaviour to determine empirical values of a factor to adjust estimates closer to actual static test results. The dependence of the empirical factor on soil type, the liquid limit of plastic soils and water content is shown. [ABSTRACT FROM AUTHOR]

The most widely used analysis method for the laterally loaded pile problem is the Winkler spring approach. Although researchers have proposed nonlinear formulations for the p-y curves, the contribution of the soil nonlinearity has not been thoroughly studied. The main drawback of the current approach is the use of a single stiffness in the p-y formulation. This study investigates the laterally loaded pile problem by employing the pressure-dependent hardening soil model with small-strain stiffness (HS-Small Model), where the degree of soil nonlinearity is better integrated. The parametric analyses are performed on the verified model for various pile and soil properties. A new p-y model is proposed for pile behaviour under monotonic loading based on the numerical analysis results. The model includes the initial stiffness, ultimate soil resistance, and degree of nonlinearity parameters. The validity of the proposed model is demonstrated by simulating a centrifuge and two field tests from the literature. The proposed model accurately accounts for soil nonlinearity and significantly improves the estimation of lateral displacements. [ABSTRACT FROM AUTHOR]

Liquefaction-induced lateral spreading is a main cause of pile failure during earthquakes because it places considerable soil pressure on piles. The lateral spreading pressure originates not only from liquefied soil but also from nonliquefied soil when it overlays a liquefied soil layer. In this study, we develop a practical lateral spreading pressure model for pseudostatic analysis to analyze pile response in inclined liquefied ground. The model comprises two parts. First, using a laminar flow model, the lateral spreading pressure of liquefied soil is modeled as the equivalent fluid flowing pressure. The coefficient of viscosity of the liquefied soil is constructed on the basis of shaking table tests in the literature. The normalized lateral spreading pressure depends on the liquefied soil thickness-to-pile diameter ratio. Second, for nonliquefied soil, individual p–y curves for uphill and downhill soils are used to simulate their distinctive soil reaction mechanisms. The uphill soil is subjected to lateral spreading soil displacement, whereas the downhill soil is subjected to pile displacement. This approach can elucidate the net soil reactions of the downhill and uphill soils that vary depending on pile stiffness. The proposed model is validated through simulations involving 1-g shaking table tests, centrifuge tests, and case histories reported in the literature. • Lateral spreading pressure of liquefied soil is modeled as equivalent fluid flowing pressure based on a laminar flow model. • The normalized lateral spreading pressure depends on the liquefied soil thickness-to-pile diameter ratio. • P–y curves of uphill and downhill nonliquefied soils are used to simulate their distinctive soil reaction mechanisms. • The stiff pile sustains larger lateral spreading pressure because of larger soil reactions from the uphill soil. [ABSTRACT FROM AUTHOR]

This paper discusses the sensitivity of predictions of the inertial and kinematic lateral response of single end-bearing piles to key assumptions of contemporary elastodynamic solutions. This is facilitated by a robust, continuous mathematical model of the dynamic response of the soil-pile system, capable of considering two extreme soil-pile interface scenarios i.e., "smooth" and "rough" boundary, as well as vanishing vertical soil displacements or vanishing vertical normal stresses. The model exploits the theory of confined elastodynamics to accurately quantify soil-pile interaction; the soil surrounding the pile is treated as a Tajimi-type continuum, while the pile is modelled as a one-dimensional elastic Euler-Bernoulli beam. Results of a parametric study with the proposed model demonstrate that the shear boundary conditions at the soil-pile interface have a noteworthy effect on the static and dynamic soil resistance and stiffness of the soil-pile system in the case of inertial loading (lateral loads applied at the pile head). On the contrary, this effect is much less prominent in the case of kinematic loading, associated with propagation of seismic shear waves in the absence of a superstructure. Findings of this study underline the importance of quantifying the effect that simplifying assumptions have on predictions of analytical methods used to model soil-pile interaction when using such methods in research and practice. • A continuum solution for lateral dynamic response of end-bearing piles is proposed. • The soil reaction and pile stiffness are compared between two extreme scenarios. • The kinematic response of piles is proved insensitive to different assumptions. [ABSTRACT FROM AUTHOR]

Tunnel construction below or adjacent to piles will affect the performance and eventually the stability of piles due to ground deformation resulting in the movement of piles and changes in the axial force distribution along the piles. A three dimensional finite element analysis using PLAXIS 3D (2013) was performed to study the behaviour of a single pile and 3 x 3 piles group during the advancement of shield tunnelling in ground. The 10-node tetrahedral elements were used to model both the soil and the tunnel lining. The Hardening Soil (HS) model was used to simulate the soil structure interaction at the tunnel-soil interface. An isotropic elastic model was used for the pile, piles cap, tunnel lining and tunnel boring machine shield (TBM). Several parametric studies were attempted including the longitudinal, lateral, and vertical tunnel location relative to pile embedded in different types of soil (clay or sand). The results showed that the pile head settlement increases during the tunnelling advancement in larger values than that for ground surface settlement. A zone of influence was determined in the range of twice the tunnel diameter in the longitudinal direction (forward and backward of the pile), and transverse direction (left and right of the tunnel centreline). If the tunnel boring is kept off this zone then there is no fear of pile collapse.

ABSTRACT Wind solicitations generate horizontal, tensile, and compressive stresses on building foundations. In empty light structures, such as agricultural greenhouses and, in the specific case of silos and elevated structures such as metal water tanks, the consideration of these loads becomes important because the lack of the weight component due to the storage load significantly influences the balance of forces. This study focused on the behavior of metallic steel profiles, aiming at its application as a foundation element for the pile, considering the soil of Diabasic origin common to the Center-South region of Brazil. Load tests in real scale were carried out on three steel profiles, type I, gauge W 250 mm x 32.7 kg m-1, drilled in the ground up to 12m deep by means of a pile driver. One steel profile was submitted to lateral loading, another to vertical compressive loading, and the other to vertical tensile load. Test results determined the bearing load of the pile for each loading type, calculated the soil reaction coefficient for lateral loading, and verified the applicability of load capacity prediction methods to tensile and compressive strengths of piles, commonly used in foundation projects.

The use of optical fiber for measuring strain and or temperature is increasing in civil engineering. Optical fiber is known to be relatively cheap, compared to the more traditional sensors commonly used, and can, depending on the chosen technology, give a complete distribution along the instrumented element, which can be very interesting in case of an element with variable dimensions along the length of said element. Therefore, for static pile loading tests, the use of optical fiber should present many advantages, compared to more conventional methods of strain measurements. The aim of this paper is to shed new light on the advantages and disadvantages of using optical fiber for the measurement of deformations along a foundation element. After a review of the state of the art of the most commonly used methods, the contribution of the optical fiber for the instrumentation of the foundation elements is evaluated, by comparing the results obtained by the use of the fiber with those obtained with more traditional methods, in some examples of full-scale load tests. Finally, some recommendations are given to maximize the awareness of the potential use of optical fiber in foundation monitoring. [ABSTRACT FROM AUTHOR]

Soil reinforcement includes a set of techniques in order to improve its mechanical or physical properties, by the establishment of inclusions working on traction, compression or bending. Among these techniques are nailing, tie rods, micro piles, bored piles, ballasted columns. Slope stability can be improved with different ways using soil improvement techniques or by installing supporting structures such as retaining walls or piles. The first solution leads to the reduction of forces that cause sliding; the other solutions generally lead to the increase of resistance forces. The present work is concerned with the sensitivity of the deformations of contiguous drilled pile walls reinforced by tie rods associated with the models of soil behaviour. The analysis is done on the metro station of Algiers Line 1, Extension C-Hai el Badr-Ain-Naadja (station of Ain-Naadja). The obtained results by a numerical simulation in 3D, deformations at the level of the piles or displacements, as well as the efforts of extensions at the level of the tie rods are compared with the measurements in situ taken in very particular points either at the level of the tie rods or by inclinometers at the level of the piles. [ABSTRACT FROM AUTHOR]

Numerical investigation on the influence of reaction piles regarding static load test results The present paper investigates the influence of reaction piles on the load‐settlement behavior of the test pile during static load testing by means of a numerical study using FEM. In this investigation mainly the parameters distance between piles, pile length, length of reaction piles in comparison to the test pile's length as well as the number of reaction piles are varied. It is found out that the recommendations of the working group piles (EA Pfähle) regarding the minimum distance between test and reaction piles is not sufficient to avoid an influence of the reaction piles on the test pile's bearing behavior. [ABSTRACT FROM AUTHOR]

A newly developed design concept for plane earthwork structures on pile foundations is presented. This design concept is based on a complex mathematical background that has been derived using fundamental mechanical principles. The mechanical system comprises the arching effect in a plane earthwork structure on punctual supports. It incorporates the effect of an elastic membrane that is formed by orthogonal ribs of geogrids, the modulus of subgrade reaction between the piles and the elastic settling of the piles. Some practical design examples are shown. The important aspects of the analysis and the design are pointed out. The complete mathematical background and a comprehensive design tool for free use have been prepared and are provided through a download link: https://gft‐pes.blogspot.com. [ABSTRACT FROM AUTHOR]

A new forecast method is proposed in order to improve the estimation accuracy of the ultimate bearing capacity (UBC) of single driven piles. The performance of the adaptive neuro-fuzzy inference system (ANFIS) and multilayer perceptron (MLP) models have been boosted using gray wolf optimization (GWO). To train the models, data were used from 100 driven piles in c-φ soil in different locations. The input parameters were pile area (m2), pile length (m), flap number, average cohesion (kN/m2) and friction angle (°), average soil specific weight (kN/m2) and average pile–soil friction angle (°), and the output was UBC. The results showed that both the MLP and ANFIS methods had good abilities to predict the UBC of the piles; however, the MLP-GWO model with a topology of 7 × 10 × 10 × 1 provided better results. The performance indices of this model were a RMSE of 1.86 kN and R2 of 0.991 for the test data. The validity of the MLP-GWO model was tested using a new experimental dataset, and the difference between actual and estimated UBC was very low (about 2%) and confirmed the high accuracy of the model. It was observed that the theoretical methods underestimated the UBC significantly, while the proposed model estimated the UBC with high accuracy. Sensitivity analysis confirmed that the pile area and length were the most effective factors for estimation of UBC. [ABSTRACT FROM AUTHOR]

The aim of this paper is to compare between results of the 2D finite element method (FEM) and results of the 3D (FEM) when they are used to assess the factor of safety of clay slopes stabilized with vertical piles. It is expected that this comparison will aid engineers to judge and convert the results of the simplified 2D analysis to the more realistic results of the sophisticated 3D analysis that simulates the real behavior of slopes having infinite length. Extensive numerical modelling of homogeneous clay slopes stabilized with a row of piles and underlined by a bed of rock are carried out using the PLAXIS 2D program (version 8.2) and the PLAXIS 3D program (version 2010), which are both based on the shear strength reduction method to evaluate the factor of safety of the slope. The increase in factor of safety (FSI) of the stabilized clay slope is investigated considering many parameters, which include, the slope width, location of the piles, piles diameter, piles spacing and shear strength of the clay. Results of both PLAXIS programs are presented and compared in terms of increase in the FSI % relative to cases of slopes without stabilizing piles. [ABSTRACT FROM AUTHOR]