Bearing Capacity Of Pile Foundation Research Articles

Comparative Analysis of Bearing Capacity of Pile Foundation Using Van Der Ween, Philipponnat, and Meyerhof Methods

Soil has different characteristics so that it becomes a lot of problems in Civil Engineering construction, especially in foundation planning, it must be done carefully and use several methods as a comparison. This research is to compare the three methods of calculating the bearing capacity of bored pile foundations: Van Der Ween, Phillipponnat, and Meyerhof. The selection of an apposite method in bearing capacity analysis is important to confirm the safety of the building structure. The Van Der Ween Method is a more modern and detailed approach compared to the Meyerhof Method, it takes into account the negative impact of the lateral deformation of the pile, which improves the accuracy of its calculation. The Philipponnat Method is a method that combines aspects of both the Meyerhof Method and the Van der Ween Method, it considers load characteristics and soil properties like Meyerhof, while also accounting for lateral deflection of the piles like Van der Ween. The results show that each method has advantages and disadvantages in determining the bearing capacity of bored pile foundations. Analysis revealed factors such as pile diameter, soil depth, and maximum applied load affect the accuracy of the three methods. This research provides important insights for construction planners in selecting a suitable method for bored pile foundation bearing capacity analysis. It is recommended that soil characteristics and pile geometry be considered before selecting the most appropriate calculation method. This research can be extended by considering other methods and conducting validation through experimental analysis.

Bearing Capacity Analysis of Pile Foundation in Reservoir Construction

The foundation was an important part of the structure. In foundation design, it was necessary to considered the foundation condition to be built must be able to support the load up to the allowable capacity. To determine a safe foundation requires analysis using several of static methods. This research was conducted to obtain a critical bearing capacity so that it can be used to determine a very safe foundation. In this study, analysis of the bearing capacity of pile foundations was calculate using the method of Briaud et al. (1985), Meyerhof (1956), Decourt (1982), Shioi & Fukui (1982) based on SPT N-value obtained from the field at borehole 1 (BH-01) and borehole 2 (BH-02). Based on the analytical result of the bearing capacity calculation of a pile foundation with a diameter of 0.35m on depth of 24m, The lowest of bearing capacity (critical value) used to determine the number of piles is the method of Briaud et al. (1985) was 90.55 tons at borehole 1 and 87.06 tons at borehole 2. This value was use as a guideline for determining the number of pile foundations used in reservoir construction design.

Field test study of a novel solar refrigeration pile in permafrost regions

Cast-in-place piles are popular foundation forms in permafrost regions. The freezing force at the pile-soil interface is the main source of bearing capacity, which is quite sensitive to ground temperature. The warming climate and engineering activities can cause the permafrost to thaw, affecting the long-term stability of the pile foundation. However, the method of cooling pile foundations is rarely reported. This paper proposes a solar refrigeration pile consisting of a solar power system, a compression refrigeration system, and a concrete pile to control the surrounding permafrost temperature. A field test was conducted in the Qinghai-Tibet Plateau permafrost regions to assess the actual cooling performance. The test results showed that the new pile effectively cooled the surrounding permafrost in the warm season without human intervention. After 10 days of cooling, the influence radius of the solar refrigeration pile exceeded 1 m. Furthermore, the solar refrigeration pile significantly improved the bearing capacity. This study provides a practical solution for addressing the challenge of maintaining the stability and bearing capacity of pile foundations in permafrost regions under the influence of climate change and human activities.

Research on dynamic p-y curves in liquefied sand under cyclic loading conditions

Under dynamic cyclic loads, the pore water pressure in saturated sand rises continuously, which leads to the reduction of horizontal bearing capacity or the damage of the pile foundation. Under dynamic cyclic loads, the existing calculations methods of horizontal bearing capacity of pile foundations were obtained by proposing a reduction factor for the static p-y curve model mostly. Compared with the test results, the soil resistance around the pile obtained by this method is often overvalued and the pile-soil relative displacement has a relative underestimation. As a result, this method is not suitable for pile foundation design. Therefore, the variations of soil resistance around the pile and the pile-soil relative displacement are obtained by analyzing the effect of pore pressure ratio on soil strength around the pile in saturated sand in this paper. The theoretical formulas related to the cyclic vibration times and pore pressure ratio are proposed. The proposed formulas are introduced into the dynamic p-y curve model to obtain the dynamic p-y backbone curve in the process of sand liquefaction. The research results show that the variations of the soil resistance around the pile and the pile-soil relative displacement are related to the pore pressure ratio and the cyclic vibration times during the sand liquefaction. As the cyclic vibration times increases, the pore pressure increases, the soil resistance around the pile decreases and the pile-soil relative displacement increases.

Review of research progress on key disposal techniques of pile foundation in karst area

It is necessary to study the key disposal technology of pile foundation in karst area during the development of pile foundation. In this paper, the development status of the key disposal technology of pile foundation was compared and analyzed from two aspects: the research progress of the comparison and selection of pile foundation design and construction scheme, the problems encountered in the construction of pile foundation in karst area and the research progress of treatment methods. The shortcomings and problems in the research of key disposal technology of pile foundation in karst area were studied, and the following conclusions were drawn: It is the priority among priorities to formulate scientific and quantitative reference basis for pile foundation construction scheme and convert engineering geology into data information. It is an important way to solve the problem of pile foundation construction in karst cave area to develop new piles and increase their adaptability to geological conditions. In the construction of pile foundation in karst area, the probability of accidents should be reduced as much as possible and the possible accidents should be stopped at the prevention stage. The research results provide technical support and scientific guidance for the calculation of bearing capacity of pile foundation and the key disposal technology in karst area.

Analysis of Complex Tests of the Module Piles in Difficult Soil Ground

The purpose of the scientific work is comparative analysis using Static compression load test (SCLT) and Dynamic load test (DLT) methods to determine of bearing capacity of pile foundations in difficult soil ground. Mega project is the construction site of Cargo offloading facilities (COF) in Atyrau region. In project used 2 consists module piles. Precast concrete module piles have 16 meter piles and 11.5 meter (9.5 m) piles with joint a total length of 25.5 m and 27.5 m, cross section 40×40 cm. The design of pile foundations was carried out in accordance with the requirements of regulatory standards. DLT testing method is also need for assessment of bearing capacity for module piles. Numerical modeling of piles was carried out in the Plaxis 2D program. The interaction of module piles with difficult of soil ground of West Kazakhstan is presented.

Prediction of Ultimate Bearing Capacity of Pile Foundation Based on Two Optimization Algorithm Models

The determination of the bearing capacity of pile foundations is very important for their design. Due to the high uncertainty of various factors between the pile and the soil, many methods for predicting the ultimate bearing capacity of pile foundations focus on correlation with field tests. In recent years, artificial neural networks (ANN) have been successfully applied to various types of complex issues in geotechnical engineering, among which the back-propagation (BP) method is a relatively mature and widely used algorithm. However, it has inevitable shortcomings, resulting in large prediction errors and other issues. Based on this situation, this study was designed to accomplish two tasks: firstly, using the genetic algorithm (GA) and particle swarm optimization (PSO) to optimize the BP network. On this basis, the two optimization algorithms were improved to enhance the performance of the two optimization algorithms. Then, an adaptive genetic algorithm (AGA) and adaptive particle swarm optimization (APSO) were used to optimize a BP neural network to predict the ultimate bearing capacity of the pile foundation. Secondly, to test the performance of the two optimization models, the predicted results were compared and analyzed in relation to the traditional BP model and other network models of the same type in the literature based on the three most common statistical indicators. The models were evaluated using three common evaluation metrics, namely the coefficient of determination (R2), value account for (VAF), and the root mean square error (RMSE), and the evaluation metrics for the test set were obtained as AGA-BP (0.9772, 97.8348, 0.0436) and APSO-BP (0.9854, 98.4732, 0.0332). The results show that compared with the predicted results of the BP model and other models, the test set of the AGA-BP model and APSO-BP model achieved higher accuracy, and the APSO-BP model achieved higher accuracy and reliability, which provides a new method for the prediction of the ultimate bearing capacity of pile foundations.

Calculation Model of Vertical Bearing Capacity of Rock-Embedded Piles Based on the Softening of Pile Side Friction Resistance

Rock-socketed pile is widely used in coastal wharf, Marine bridge, and Marine power engineering, and the end bearing function is considered more in the design process. However, the lateral friction resistance of rock-socketed piles is an important bearing part, and the load transfer mechanism of the pile–soft rock interface is an important research focus. In this paper, a comparative analysis was adopted in the test, and ten groups of test specimens were made, including five groups of natural and saturated mudstone specimens, respectively. The characteristics of interfacial load transfer were analyzed through the shear test of a pile–mudstone interface. A calculation model for the vertical bearing capacity of rock-socketed piles based on the softening of lateral friction resistance was established, and the effects of interface relative displacement, lateral positive pressure, pile length, and pile stiffness on the vertical bearing capacity of rock-socketed piles were analyzed. The results show that the shear strength of the pile–rock interface is lower than that of the mudstone interface, and the interfacial shear strength shows the characteristics of “first increasing, then decreasing, and finally flattening with the increase of shear displacement”. The vertical ultimate bearing capacity and residual bearing capacity under saturation were 89.49% and 89.73% of the natural state, respectively. With the increase of pile side pressure, the proportion of pile side friction resistance increased by 39.96%, and the pile side friction resistance was fully exerted. With the increase of pile length, the vertical ultimate bearing capacity of pile foundation increased, and the residual bearing capacity change value increased from 6.80% to 16.97%. However, the increase in pile stiffness had little effect on the vertical bearing capacity. The calculation model can provide a certain reference for the design and calculation of rock-socketed piles in soft rock areas.

EXPERIMENTAL STUDY OF THE BEARING CAPACITY OF PILE FOUNDATIONS UNDER CONDITIONS OF FROZEN SOIL WARMING

In recent years, an increase in average annual air temperatures has been recorded. Buildings collapsed in the northern regions, but the exact causes were not reported. However, it can be assumed that this is due to climate warming. Hence, there is a need to study the issue of the bearing capacity of piles in new conditions. The article deals with the actual problem of increasing the bearing capacity of pile foundations in the conditions of warming of frozen soils. The purpose of the article is to experimentally study models of anchor piles, the structural arrangement of which will increase the bearing capacity of pile foundations. To prevent the vertical settlement of the pile, a method is proposed, the essence of which consists in the device of stops (anchors) fixed on the factory pile. Experimental studies have been carried out with a comparison of the bearing capacity between models with and without anchors, as well as a study of the bearing capacity of the end face of the pile model. In the course of the preliminary experiment with pile models, the following production methods were worked out: wells, pile models with anchors, anchor structures, as well as a method for measuring the settlement of the pile model. It has been established that the butt of the pile model does not provide a significant increase in the bearing capacity of the pile. As a result of the experiment, it was revealed that the use of one anchor in the design of the pile model is not enough to increase the bearing capacity of the pile structure. As a result of preliminary experiments, it was found that preliminary drilling of wells leads to filling them with water, which excludes the possibility of assessing the study of the bearing capacity of the end of the model.

Summary of Research on Horizontal Bearing Capacity of Pile Foundation in Soft Ground

Based on the research theory and existing research methods of the horizontal bearing capacity of pile foundation in soft ground, this paper describes the current situation of the theory used to study the horizontal bearing capacity of pile foundation in soft ground at home and abroad, and then describes the current situation of the CPTU test method, DPP-BOTDA technology and numerical simulation methods applied to pile foundation monitoring, These research methods are proposed to provide some guidance for the follow-up research of similar projects.

Experimental study on the effects of triangular groove inclination angles on the mechanical behavior of sand–concrete interfaces

The mechanical properties of pile–soil interfaces directly affect the bearing capacity of pile foundations. In this study, the effects of triangular groove inclination angles on the mechanical properties of sand–concrete interfaces were investigated. Random rough concrete surfaces were obtained through slurry intrusion testing, and the roughness of concrete surfaces was evaluated based on the sand cone method. According to the roughness of random concrete surfaces, five regular concrete surfaces with different triangular groove inclination angles were constructed. A series of direct shear tests between (i) sand and random concrete surface, (ii) sand and regular concrete surface, as well as (iii) sand and smooth concrete surface were performed. Moreover, a direct shear test of natural sand was conducted. Lastly, a shear strength model considering the triangular groove inclination angle of sand–concrete interfaces was established, and the shear failure mechanism of interfaces was discussed. The results firstly indicated that the shear stress-displacement curves of random rough concrete surfaces were ideal elastic-plastic curves; and the regular rough concrete surfaces were found to incur strain softening under a normal stress of 300 kPa. Secondly, the shear strength of sand–concrete interfaces increased with the increase in groove inclination angle of concrete interfaces. Thirdly, sand was found to achieve the highest shear strength, while sand–smooth concrete interfaces proved to attain the lowest. Lastly, the internal friction angle value of random concrete interfaces was shown to range between the values of concrete surfaces with triangular groove inclination angles of 70° and 90°.

Field observation of the thermal disturbance and freezeback processes of cast-in-place pile foundations in warm permafrost regions

The bearing capacity of pile foundations is affected by the temperature of the frozen soil around pile foundations. The construction process and the hydration heat of cast-in-place (CIP) pile foundations affect the thermal stability of permafrost. In this paper, temperature data from inside multiple CIP piles, borehole observations of ground thermal status adjacent to the foundations and local weather stations were monitored in warm permafrost regions to study the thermal influence process of CIP pile foundations. The following conclusions are drawn from the field observation data. (1) The early temperature change process of different CIP piles is different, and the differences gradually diminish over time. (2) The initial concrete temperature is linearly related with the air temperature, net radiation and wind speed within 1 h before the completion of concrete pouring; the contributions of the air temperature, net radiation, and wind speed to the initial concrete temperature are 51.9%, 20.3% and 27.9%, respectively. (3) The outer boundary of the thermal disturbance annulus is approximately 2 m away from the pile center. It took more than 224 days for the soil around the CIP piles to return to the natural permafrost temperature at the study site.

Model Test Study on the Load-bearing Behaviour of Multi-tooth Piles under Different Bearing Layers

In soft soil or karst areas, several problems exist, such as the poor properties of the pile tip bearing layer or difficulties in cutting the rock. Using multi-tooth piles, end-bearing piles can be turned into friction piles to solve these problems. Through the scale model device, three variables: the bearing layer, tooth length, and tooth number, are designed to experimentally explore the load-bearing behaviour of multi-tooth piles under different bearing layer conditions. The test results show that the model pile has better anti-settlement performance in the sand bearing layer than in the red clay bearing layer. Compared with smooth piles, multi-tooth piles can greatly improve the bearing capacity of pile foundations in bearing layers with poor stiffness. The tooth length and tooth number greatly impact the compressive bearing capacity and the pile-side resistance of the multi-tooth pile, respectively. The concept of roughness is innovatively introduced to quantify the roughness of pile surfaces, which provides an effective method for the subsequent experimental and theoretical research of multi-tooth piles and other similar piles with small cross-section modifications. This study can enrich the research field of small, modified cross-section piles and provide a reference for innovative research on pile foundations.

SCIENTIFIC AND TECHNICAL SUBSTANTIATION OF SOIL BASES STRENGTHENING WITH REINFORCED SOIL-CEMENT PILES

Purpose. The aim of the work is to substantiate the technological parameters of effective use of reinforced soil-cement piles obtained by jet mixing technology. Such studies are needed to determine the possibility of increasing the bearing capacity of pile foundations in the body of earthen structures of buildings and roads. Methodology. Determination of bearing capacity of reinforced soil-cement piles was carried out by reasonable choice of structure, soil base, material, depth of piles in accordance with engineering and geological conditions, structural scheme of the structure and method of their arrangement. Findings. Significant differences in soil engineering and geological elements in plan and depth necessitated an in-depth study of soil characteristics, so it was decided to determine their strength and deformability based on static probing of reinforced piles. Analysis of the results of static studies showed that the soil-cement pile, reinforced with a reinforcing frame, has a higher bearing capacity in soil and material, and the unloading branch confirms the fact that in specific conditions the soil and piles work in elastic mode. Originality. It consists of the obtained dependences of the change of vertical loads on the reinforced soil-cement pile, created on the basis of brown mixing technology. Graphs of the dependence of the values of deformations occurring during the action on the reinforced soil-cement pile under static loading and unloading are obtained. Practical value. In practical conditions, the solution for the manufacture and testing of static load of the experimental reinforced soil-cement pile was implemented at the construction site. The manufacturing technology is designed so that the spatial frames of the soil-cement element with a length of 5…7 meters are immersed under their own weight, and the frames of 12 and more meters are lowered with a vibrator.

Restoration of the bearing capacity of the pile foundation of the bridge to ensure its operational reliability

The article presents a method for restoring the bearing capacity of pile foundations as one of the components of comprehensive monitoring of transport infrastructure facilities. It gives examples of systems for the technical condition monitoring of bridges, and outlines innovative approaches to strength monitoring. Using one of the piers of a railway bridge as an example, the latest technologies of survey and calculation of the pile foundation are applied. The testing laboratory performed work on the survey of the piles structure after completing the pile foundation construction for the bridge piers. The concrete continuity of piles and the presence of void pockets and decompaction in the concrete were to be determined. The bearing capacity of the pile footing was calculated and the design loads were determined. The study provides design models of the pile foundation, external loads, and the method statement. Hydrological conditions corresponded to those referred to in design documentation being part of the report on geological engineering surveys. The analysis of calculations revealed an increase in the sectional strength utilization rate in the “hollow” zone of the pile, taking into account the construction and further operation of the bridge, calling for special measures to strengthen the pile foundation. Then, the measures to restore the bearing capacity of the pile foundation and a brief description of the drill and inject technology are given. Upon completion of the drill and inject operations, the bearing capacity of the pile footing was calculated taking into account the stabilization of the soil mass and the pile strengthening. At the end of the study, the conclusion about the feasibility of the measures taken and on securing the bearing capacity and operational reliability of the bridge foundation piles is made.

ИННОВАЦИОННЫЕ СВАЙНЫЕ ТЕХНОЛОГИИ В СОВРЕМЕННОМ ФУНДАМЕНТОСТРОЕНИИ

Pile technologies in modern foundation engineering are the leading direction for improving their constructive and technological solutions. The bearing capacity of pile foundations largely depends on the formation of the frictional force of the soil along the lateral surface of the piles. The authors considered technologies for the construction of transformable piles using non-explosive destructive substances, modular piles with a developed lateral surface and an optimal cross-section, piles using geopolymer technology and piles that allow changing the granulometric composition of the adjacent soil. The results of laboratory studies of the models of these piles are given, the effectiveness of their application is established and methods for calculating their bearing capacity are proposed, the directions of research activities are indicated. The studies carried out allow us to conclude that the comparison of the specific bearing capacity of driven piles of different cross-sections showed that the most rational section is tavrovoe. The developed, approved and registered "Technical conditions for modular driven T-shaped piles" make it possible to manufacture, transport, and drive this type of piles for industrial and civil construction. Options for the layout of foundation systems based on modular T-section piles are proposed, depending on the nature of the load acting on them.

Uncertainty Analysis of Axial Pile Capacity in Layered Soils by the Piezocone Penetration Test

This study presented a framework for uncertainty analysis of the ultimate axial bearing capacity of piles evaluated by the UniCone method in layered soils. The UniCone method by Eslami and Fellenius (1997) is a direct piezocone penetration test (CPTU) method for evaluating the ultimate axial capacity of piles in the reliability design. The spatial variability of CPTU data is modeled as a random field for each soil unit in the soil strata. The empirical correlation coefficients of the UniCone method are assumed to follow lognormal distributions. On the basis of uncertainties of CPTU data and empirical correlation coefficients, the first-order reliability method (FORM) is then applied to the reliability analysis of ultimate axial bearing capacity of piles. The effects of spatial variability of CPTU data and variations of empirical correlation coefficients on the ultimate axial bearing capacity of piles are evaluated by an Excel spreadsheet-based framework. Seven case studies show that the proper identification of different soil units from soil profiles is crucial for estimating the failure probability of pile capacity in the reliability analysis. Uncertainties of CPTU data and empirical correlation coefficients would be over-estimated unless different soil units in soil profiles are identified properly from each other. The over-estimated geotechnical parameters contribute to a higher failure probability of pile capacity. The proposed framework can evaluate the uncertainty of the ultimate axial bearing capacity of pile foundations more rationally.

ANALISA STRUKTUR ABUTMENT UNDERPASS JALAN NASIONAL STA 6+850 PROYEK JALAN TOL RUAS BINJAI – LANGSA SEKSI BINJAI – PANGKALAN BRANDAN

Prestressed concrete bridge STA 6+850 Provincial Road Penggal Binjai-Langsa Freeway is one of the footbridges connecting the fast road from Binjai To Langsa with a total bridge length of 30 meters and a total bridge width of 26.90 meters (2 lanes). Preparation of the prestressed walkway for Provincial Road STA 6+850 Freeway at the Binjai-Langsa joint is based on RSNI-T-02-2005 for loading on the walkway. Based on RSNI-T-02-2005, the loading for the prestressing walkway spans 30 meters with a total of 3 tendons, where one tendon is 19 standards with a diameter of 12.7 millimeters. The tension in the flexural compression fiber due to the influence of prestressing, dead load and live load is 0.45 fci' (13500 kPa). Control of overturning stability in the X and Y directions on the abutment, the number of safety (SF) against overturning is greater than the allowable SF = 2.2 (safe). The carrying capacity of the pile foundation bearing capacity (Qg) was analyzed based on SPT data, the value obtained was 87207.33 kN using Meyerhoff's (1956) method from SPT field data.

Efficiency Analysis of Foundation System

The increasing number of residents in South Tangerang has an impact on increasing the need for lower housing. The development of vertical housing with the market name of flats, apartments and is the most effective anticipatory solution to overcome land prices which result in market limitations, especially for the upper middle class. This 32-storey apartment project uses a combined foundation system between drill pile foundation & raft foundation. With the combination of these two very massive systems, of course, it will have a very expensive cost to implement and take a long time to complete. In order to avoid cost overruns, the foundation design must look at the possibilities. To determine the efficiency of the combined system foundation design between pile bored foundation & raft foundation, the researchers analyzed the value of the bearing capacity and also the settlement that occurred in the existing foundation using the Poulos method, the equivalent Raft method and the Vesic method. From the results of the study, it was found that the contribution of the pile foundation bearing capacity was 24.10%. the placement of the raft foundation is 75.90% and the settlement analysis using the Poulos 8.95cm method, the 12.41cm Equivalent Raft method and the Vesic 12.1cm method, these three results are close to the maximum settlement limit.

Theoretical Analysis on the Vertical Bearing Characteristics of Pile Foundations Containing Sediment Defects

Abstract Aiming at the situation that the bottom of the pile foundation contains sediment defects, the theoretical analysis of the vertical bearing characteristics of the pile foundation is carried out. Based on the load transfer mechanism of the pile-soil system and based on the load transfer function of the elastoplasticity of the soil on the side of the pile and the weakening of the trifold line of the soil at the end of the pile, a load transfer calculation model for bored cast-in-place piles with slag defects under different conditions was established. The corresponding analytical formulas are deduced, and the accuracy and reliability of load transfer derivation are verified in combination with calculation examples, which are suitable for indoor and field tests. The influence coefficient of sedimentary defect in single pile is defined, and the parameters are analyzed. The law about the influence coefficient of length-diameter ratio, the thickness of sedimentary defect, and the modulus of elasticity of sedimentary defect in single pile are obtained: With the increase of the ratio of length and diameter, the defect coefficient of single piles gradually increases and tends to ease, and the bearing effect of pile foundations is more convergent. As the thickness of the sediment increases, the influence factor of the single pile defect gradually decreases, and the influence factor of the bearing capacity of pile foundation becomes more discrete. With the increase of the elastic modulus of sediment, the influence factor of single pile defect gradually increases, and the ultimate bearing capacity loss decreases. The vertical bearing characteristics of the pile foundation are evaluated in this way, which provides an important reference for further analysis of the bearing characteristics of pile foundations with slag defects.