Calculation Of Bearing Capacity Research Articles

Perbandingan Metode Bishop dan Janbu dalam Analisis Stabilitas Lereng pada Oprit Jembatan Labu Sawo Sumbawa

The oprit pile of Labu Sawo Bridge has a height of about 9.70 m with a length of 125 m, planning the labu sawo bridge oprit there is a problem in the subgrade is a type of clay soil which is not good because it has low soil bearing capacity, high moisture content and cracks (DPT) due to landslides so that they have the potential to experience ground movement and shifting. Therefore, calculation of slope stability and soil bearing capacity needs to be done to determine how much the slope safety and bearing capacity of the embankment soil. In the calculation of the analysis, the method used to find the safety value (SF) of the embankment slope is the Bishop and Janbu method. From the results of the method used, the security number given is calculated and then the safety figure is calculated. Based on the calculation results, the oprite embankment slope is categorized as a stable slope with the safety value of the Bishop method of 1.262. while the slope stability analysis used the Janbu method of 1.455 from the Bishop and Janbu method, the oprite slope of the Labu Sawo Bridge was categorized as slope in stable condition. Keywords : Slope stability, Bishop, Jambu.

Experimental Study on the Bending Behavior of Steel-Wood Composite Beams

This paper proposes a steel-wood composite beam with H-shaped steel beam webs glued to the wood. As a new type of composite beam, it combines the advantages of low energy consumption of wood, high permeability, and less pollution and the advantages of light weight and high strength of steel, high degree of assembly, short construction period, and less construction waste generated. Carrying out research is of great significance to improve the mechanical properties of steel-wood composite beams and promote the development of steel-wood composite structures. In this paper, three hot-rolled H-beam-larch composite beams and one pure steel beam were tested for bending capacity. The composite beams are divided into two different combinations of A and B types. The two sides of the web are connected with larch wood by structural glue to form a composite beam. The type B composite beam is a larch wood glued on both sides of the H-shaped steel web and penetrates the bolts at the same time. Through the three-point monotonic static grading loading of the composite beam, the deflection change, failure phenomenon, and form of the specimen during the experiment were observed. Under the circumstances, the ultimate bearing capacity of the test piece was changed to study the combined effect of larch and hot-rolled H-shaped steel. The results show that the overall performance of the H-shaped steel-larch composite beam is good. Bonding wooden boards on both sides of the steel beam web can improve the bearing capacity, and the form of the member is more reasonable and effective; increasing the cross-sectional size of the H-beam in the steel-wood composite beam can further improve the bearing capacity of the composite beam; adding bolt anchorage on the basis of the structural glue used in the composite beam can further improve the bearing capacity of the composite beam. The superposition principle is used to simplify the calculation of the ultimate bearing capacity of H-shaped steel-larch composite beams. Comparing the calculation results with the test results, the data are in good agreement, which can provide a design reference for the practical application of such composite beams.

STUDY ON SHEAR BEARING CAPACITY OF COLD-FORMED STEEL COMPOSITE WALLS WITH LIGHTWEIGHT GYPSUM FILLINGS

In order to calculate the shear bearing capacity of cold-formed steel (CFS) composite walls with lightweight gypsum infillings, the full scale specimens including two unfilled walls and nine infilled walls were tested under reversed cyclic loading. The failure modes of the walls under horizontal loads were studied. The test results show that the failure modes of unfilled CFS walls are characterized by the screw connections between sheathings and CFS frames, thus causing the loss of stressed skin provided by sheathings. There are two possible failure modes of CFS walls with fillings. One is the compressive failure at the corner of gypsum fillings, and the other is the flexural failure of CFS studs. According to above-mentioned failure modes and limit equilibrium theory, a shear bearing capacity calculation model based on superposition method is proposed considering the contributions of sheathings and infill materials. Then the calculation equations of shear bearing capacity are also derived. The model can reflect the impact of screw connections strength, infill material strength and CFS frames strength on shear bearing capacity of the walls. The ratios of the theoretical calculation values to the test values are between 0.947 and 1.112, which demonstrates that the theoretical calculation values have a good agreement with tests values.

Seismic performance and damage evaluation of spiral ribbed thin-walled concrete filled and encased steel tube composite columns

As a new type of composite components, thin-walled concrete-filled steel tubes (CFSTs) have some advantages in terms of economy and processing. After the steel tube wall thins, the local buckling performance decreases and the stiffness decreases, which is not conducive to the structural safety. In this paper, combining the advantages of traditional spiral hoops and a stiffener, a new constraint in the form of a screw stiffener was proposed. On this basis, the composite member of thin-walled CFSTs with spiral ribs was put forward. The horizontal hysteretic test was carried out for the new composite column, and the failure mode, hysteretic characteristics, ductility, and energy dissipation capacity were obtained. The results showed that, compared with the traditional form, the seismic bearing capacity of the new composite column was increased by 11% and the ductility was increased by 45%. The deformation capacity was significantly improved. Based on experimental research, the seismic bearing capacity calculation and seismic damage assessment of the composite column were studied, and the practical calculation and the two-parameter damage assessment method considering the interaction between deformation and energy were proposed, which were in good agreement with the test results. This study can provide a technical basis for its engineering application. The composite column has good seismic performance, durability, and fire resistance, and thus has potential for application in practice.

Bearing Capacity Prediction of Mine Hauling Road Using Cone Penetration Testing (CPT)

Mine hauling road plays an important role in open pit mining that serves as the main link for transports to significant locations, such as connection from pit/quarry – crusher – stockpile/rom – jetty. Inadequate bearing capacity could result in construction failure of the haul road, therefore it is important to understand the bearing capacity of the sub base layer along the determined haul road route. Cone Penetration Test (CPT) was utilized to obtain the insitu geotechnical data used for determining the haul road bearing capacity. Results show that the occurrence of hard layer along the haul road route varies from the depth of 3.40 (CPT12) to 12.20 m (CPT06). Calculated bearing capacity of the sub base layer shows varying results along the road route. Minimum ultimate bearing capacity (qul) of 430.49 kN/m2 is found in CPT-06 site with allowable bearing capacity (qall) of 215.24 kN/m2. While maximum ultimate bearing capacity (qul) occurs in CPT-04 site of 2058.71 kN/m2 with the allowable bearing capacity (qall) of 1029.35 kN/m2. The calculated average ultimate bearing capacity (qul) is 1151.47 kN/m2 and allowable bearing capacity (qall) 575.74 kN/m2. It is suggested that the type of dump truck used for hauling should have tire pressure less than or equal to 575.74 kN/m2, in order to maintain the road during mining lifetime and prevent road deterioration.

The comparison study of the monopole tower foundation using CPT and laboratory data in Gresik district, East Java-Indonesia

In the millennial era, the development of information and communication technology is very fast, one of the telecommunications infrastructure is a monopole type telecommunications tower. This type of tower is one of 3 types of telecommunication towers whose main construction is made of steel. The monopole structure is supported by a tread foundation, which is one type of shallow foundation. The main factor in the design of the tread foundation is the bearing capacity factor. Calculation of foundation bearing capacity can be done directly in the field using Sondir data (CPT) and indirectly using laboratory data. In this study a study was conducted to compare the carrying capacity of monopole foundations between field data methods in the form of Sondir data or CPT with result data. Soil tests in the laboratory calculated with the Terzaghi formula. The research location was carried out in Gresik Regency, East Java Province, Indonesia at 3 sites, namely: Mojosarirejo, Kembangan Kebomas and Setromenganti. The results of the comparison of the calculation of the bearing capacity of the foundation (Q) at the Mojosarirejo site with the type of sandy soil. value of QSondir < 9.58 % of Qterzaghi. At the Krembangan Kebomas site with brown clay and gravely clay, the Q value was < 69.93 % of the Qterzaghi and at the Setromenganti site with brown clay soil type with the influence of water level depth – 1 m, the Q value was < 27, 62% of Qterzaghi. From the comparison of the average calculation in the 3 study locations, the bearing capacity of QSondir treads foundation is 26.50 % smaller than Qterzaghi, so the use of Sondir data is more accurate for use in tread foundation planning and provides greater security assurance for the tower foundation structure. monopole type

Bearing capacity of plane-strain footings under K0 conditions

Existing analytical solutions for estimating the bearing capacity of shallow foundation are mostly established under the K0 = 1 condition, which can produce overly conservative calculations. This investigation provides a novel approach to evaluate the behavior of a plane-strain footing under the K0 ≠ 1 condition. The additional stresses induced by the applied load are superposed with the in situ stresses due to the soil’s self-weight for calculating the major and minor principal stresses, which are then substituted into the Mohr Coulomb failure criterion to check the occurrence of plasticity. The correlation between bearing capacity and depth of plastic zone is proposed. The mathematical form of the solution is also simplified by an approximation method that follows the general form of bearing capacity calculation. The effectiveness of the developed framework is evaluated by comparing against existing approaches. Once the efficacy of the analytical model is demonstrated, a sensitivity study is conducted to study the impact of soil friction angle, cohesion, and lateral earth pressure coefficient. A term of vacuum preloading is also incorporated in the proposed solution, and an illustrative example is presented to show how the performance of a shallow foundation can be improved by the degree of consolidation.

Influence of shrinkage cracks on the mechanical properties of bolted-type glulam joint with slotted-in steel plate: Experimental study

Environmental shrinkage cracks are obviously observed in bolted-type glulam joints due to the material mechanical-physical properties and high moisture transport rate. The objective of ongoing research mainly presents an experimental study on the mechanical properties of bolted-type glulam joints with cracks. To shorten the test time and control the crack pattern, the outer moisture-induced shrinkage cracks are replaced by preset cracks. Thus, thirteen glulam joints with different preset cracks are designed and tested. The parameters are three locations (i.e., along the top bolts, neutral axis, and bottom bolts), two lengths (i.e., 140 mm, and 330 mm), three depths (i.e., 30 mm, 60 mm, and 118 mm), and two kinds of layouts (i.e., cracks on the same side and different sides). In the experiments, the loading process and failure modes of the joints were observed, the load-displacement relationships were analyzed and the residual bearing capacity of the joints was recorded. The joint exposed to the controlled climate change test showed that longitudinal cracks were easily observed along with the bolts in multiple steel-to-wood joints and four reasons were presented for this phenomenon. Furthermore, significant reduction values were observed due to cracks for joints in terms of their initial stiffness k, peak load Pmax, and displacementΔmax up to 79.3%, 75.39%, and 95.1%, respectively. Additionally, reduction coefficients were proposed for the calculation of residual bearing capacity. The calculation results showed good consistency with the experimental tests.

Bearing Capacity Factor of Circular Footings on Two-layered Clay Soils

Geotechnical engineers often deal with layered foundation soils. In this case, the soil bearing capacity assessment using the conventional bearing capacity theory based on the upper layer properties introduces significant inaccuracies if the top layer thickness is comparable to the rigid footing width placed on the soil surface. Under undrained conditions the cohesion increases almost linearly with depth. A few theoretical studies have been proposed in the literature in order to incorporate the cohesion variation with depth in the computation of the ultimate bearing capacity of the strip and circular footings. Rigorous solutions to the problem of circular footings resting on layered clays with linear increase of cohesion do not appear to exist. In this paper, numerical computations using FLAC code are carried out to assess the vertical bearing capacity beneath rough rigid circular footing resting on two-layered clays of both homogeneous and linearly increasing shear strength profiles. The bearing capacity calculation results which depend on the top layer thickness, the two-layered clays strength ratio and the cohesion increase rates with depth are presented in both tables and graphs, and compared with previously published results available in the literature. The critical depth for circular footing is found significantly less than for strip footing. Doi: 10.28991/cej-2021-03091689 Full Text: PDF

Structural analysis of pile-foundation offshore platform

This paper takes the pile-foundation platform of Dagang Oilfield in paralic zones as the research object, provides a reference basis for further selection by analyzing the advantages and disadvantages of single platform type and multi-platform type. The key structural parameters including platform load calculation, deck bottom elevation determination and ultimate bearing capacity calculation of pressurized piles are analyzed and studied. The specific ideas of pile-foundation platform design are proposed, and the analysis process and important formulas of the methods used in the design are elaborated to give the research results, which has high reference significance for the old platform to extend its service life and the construction of the new platform.

Probability distribution of bond efficiency of steel fiber in tensile zone of reinforced concrete beams

The applicability of bond efficiency of steel fiber in the flexural bearing capacity calculation of steel fiber reinforced concrete (SFRC) beams was experimentally investigated through tests on 18 SFRC beams and one reinforced concrete (RC) beam. The test results indicated that the flexural bearing capacity of SFRC beams increased significantly with the use of high-strength steel bars, and the bond efficiency of the steel fiber in the tensile zone of reinforced concrete beams according to ACI 544.4R-88 [1] is conservative for the flexural carrying capacity calculation of SFRC beams containing high-strength steel bars. The probability distribution of the bond efficiency of steel fiber in the tensile zone of reinforced concrete beams was analyzed through experimental data collected from relevant literature. The bond efficiency of different types of steel fibers with different guarantee rates was determined. A range of bond efficiency for steel fiber in the tensile zone of reinforced concrete beams was proposed to predict the flexural carrying capacity of SFRC beams.

Static and seismic bearing capacity of shallow strip foundations on slopes

In this paper the static and seismic values of bearing capacity factors for shallow strip foundations adjacent to slopes have been evaluated using the method of characteristics, accounting, through the pseudo-static approach, for the effect of horizontal and vertical inertia forces arising in the soil and transmitted by the superstructure. Differently from most of the available studies, the effect of the inertia forces in the soil, due to the seismic wave propagation, and the effect of inertia forces acting in the superstructure, due to the structural seismic response, are dealt with independently. It was also demonstrated that the above-mentioned effects can be superimposed without significant error. Original empirical formulas and, in some cases, closed-form solutions, have been provided to calculate bearing capacity factors or suitable corrective coefficients which allow accounting for slope inclination and for horizontal and vertical seismic accelerations in the soil and in the superstructure. The proposed solutions, obtained assuming Hill's and Prandtl's failure mechanisms, have been checked against those obtained through finite-element analyses and compared with results already available in the literature.

Analysis study of soil bearing capacity and settlement of single pile foundation based on N-SPT data

Foundation is a very important structural element in a building. The bearing capacity of the soil is the support for the foundation, where a foundation is defined as a most basic part of the construction of a building that transmits the load originating from the weight of the building itself and the load acting on the building to the surrounding ground. The purpose of this research is to determine the bearing capacity of the foundation and the settlement of a single pile that occurs and to determine of the size of ship’s collision force against the building. The foundation used in the construction of the Sultan Suriansyah Mosque Port is a 45 cm diameter pile foundation. The calculation of bearing capacity of a single pile was carried out using the Mayerhoff method based on the N-SPT results of 399.802 tons. The settlement of a single pile foundation using the Semi Empirical Method is 0.036 m with an allowable drop of 0.045 m. The collision force of the ship against the Port is 0.0032 tons.

Algorithm for Vertical Bearing Capacity Calculation of Rock-Socketed Piles in Karst Area Based on Load Transfer Method

Due to the complex geological conditions and many influencing factors in karst areas, this paper conducted theoretical, experimental research and calculation analysis on the design and construction of engineering piles of bridge engineering in karst cave areas. An algorithm for vertical capacity calculation of rock-socketed piles in karst area based on load transfer method was developed. The results using this new method were analyzed and compared with the results from the static load test of three engineering piles in karst area, and the differences are relatively small. Through static load tests of pile foundation in karst area and study of the side resistance of rock-socketed pile in karst area, the friction resistance of rock-socketed pile and the effect of pile-end resistance, the bearing capacity characteristics of rock-socketed pile in karst area were obtained, achieving the load-sharing effect of cave roof in a rather scientific way. In view of the failure mechanism of the karst cave roof under the pile tip and the large proportion of lateral resistance of the rock-socketed pile, a calculation model for the stability of the karst cave roof under the combined action of the side resistance of the rock-socketed pile and the pile tip resistance is proposed.

Numerical analysis for the vertical bearing capacity of composite pile foundation system in liquefiable soil under sine wave vibration

Composite pile foundation has been widely used in ground engineering. This composite pile foundation system has complex pile-soil interactions under seismic loading. The calculation of vertical bearing capacity of composite pile foundation is still an unsolved problem if the soil around piles is partially or completely liquefied under seismic loading. We have completed indoor shaking table model tests to measure the vertical bearing capacity in a liquefiable soil foundation under seismic loading. This paper will use a numerical approach to analyze the change of this vertical bearing capacity under seismic loading. Firstly, the Goodman contact element is improved to include the Rayleigh damping. Such an improvement can well describe the reflection and absorption of seismic waves at the interface of soil and piles. Secondly, the Biot’s dynamic consolidation theory incorporated an elastoplastic model is applied to simulate the soil deformation and the generation and accumulation of pore water pressure under seismic loading. Thirdly, after verification with our indoor shaking table test data, this approach is used to investigate the effects of pile spacing on liquefaction resistance of the composite pile foundation in liquefiable soil. The time histories of pore water pressure ratio (PPR′) are calculated for the liquefiable soil and the vertical bearing capacity in partially liquefied soil is calculated and compared with our indoor shaking table test data at the 3D, 3.5D, 4D, 5D and 6D cases (D is the pile diameter). It is found that the pile spacing has some influence on the extent of soil liquefaction between piles. The vertical bearing capacity varies with liquefaction extent of inter-pile soil. The optimization of pile spacing varies with liquefaction extent. These results may provide some reference for the design of composite pile foundation under seismic loading.

The bearing capacity analysis of limestone strata roof containing a shallow-buried cylinder Karst cave

The chief objective of the article is to investigate the bearing capacity of limestone strata roof containing a shallow-buried cylinder Karst cave. Firstly, taking into account the characteristics of Karst landform in China, a spatial axial-symmetrical model was established. Concurrently, the general solution of stress components was gained using Love displacement method. Subsequently, combining failure mechanism of ground collapse and the expressions of stress components, the bearing capacity calculation formula was determined. Finally, based on practical engineering, a comparison of calculation result indicates the error is less than 3.5%, which meets the proposal standard necessity in practice.

KAPASITAS DAYA DUKUNG TIANG PANCANG JEMBATAN AIR MANGGALA PRABUMULIH DENGAN METODE MAYERHOF DAN METODE ENR

Pile foundation structures in a building are generally used if the subgrade under the building does not have sufficient bearing capacity to bear the weight of the building. The data needed to analyze the bearing capacity of these piles was from the measurement results in the field in the form of SPT and calendering data. In this paper, calculated the bearing capacity of the pile analytically from the results of calendering and standart penetration test (SPT), calculated using the Mayerhoff and ENR method. And the results of the SPT calculation showed that the net weight value or N (the amount of load received by each pile) imposed on the pile was 132.04 tons, from the calculation of the pile bearing capacity ≤ 200 tons and qualified for the safety requirements of the foundation to the soil bearing capacity. From the results of the ENR method, the largest pile bearing capacity was 305.16 tons with a value of S (the number of pile penetrations of 10 blows) was 0.002 m.

Alternatif Fondasi Tiang Pancang Pada Gedung Pengendalian Penduduk dan Keluarga Berencana (P2KB) Palu

The foundation design of Pengendalian Penduduk dan Keluarga Berencana is located on Jl. R.A. Kartini No. 100, Palu City, Central Sulawesi. In field testing using 2-point of (CPT), the value of hard-ground support at 8 – 9 m below the surface and the loads of building structures of 2 (two) floor buildings that work on the foundations are quite large, this is a consideration in choosing the type of used foundation. The point of this design is to obtain the dimensions of the pile foundation and calculate the bearing capacity of the foundation permit and settlement that meet the safety requirements. The calculation for bearing capacity of the foundation is calculated using (CPT) data and soil shear strength parameter data (c and tetha). Single pile is calculation by using the Semi-Empirical method and using Brooms Method for calculating lateral force on the driven piles. The dimensions of the foundation are planned based on the load (Qv) acting on the entire foundation. Calculation of bearing capacity of a single pile with a penetration depth of 8,20 m and varying dimensions are used in the planning. Based on the calculation of the bearing capacity of a single pile using (CPT) data on the load that works on the foundation, was obtained 25 cm and 30 cm diameter of pile. while the calculation uses ground shear strength parameter data (c and tetha) obtained pile diameter of 30 cm and diameter of 35 cm. Based on the calculation of the bearing capacity of a single pile, the dimensions of the foundation and the settlement in permits has reached the safety requirements.

Methodology for calculate bearing capacity of soft soils under cyclic loading

The bearing capacity in soft soils under cyclic loading has not been widely studied as the static bearing capacity. In soft saturated soils under cyclic load, the phenomenon of cyclic softening occurs, this consists of an increase in the generation of pore-water pressure due to the cyclic load and a decrease in effective soil stresses. The purpose of this work was to propose a methodology for calculating the bearing capacity in soft soils under cyclic loading. The research is based on the results of monotonic and cyclic simple shear tests carried out with samples from the PRAT port of Barcelona. From an analysis carried out on all the experimental data, an equation for the generation of pore-water pressure is proposed. This formulation was implemented in the FLAC2D finite difference software and is part of the methodology. The methodology of the proposed calculation process consists of 6 stages and verification under two criteria. This process is iterative in case of not meeting any of the two verification criteria. Under this methodology of the calculation process, charts are proposed to calculate the bearing capacity of soft soils under cyclic loading. This application takes into account the properties of the soil, the static bearing capacity (P he), and the effective load outside the foundation (q). Also, an analysis of the parameters that most influence the bearing capacity of soft soils under cyclic loading was carried out.

Calculation of Inter-Column Slabs Bearing Capacity by Kinematic Method

The method of bearing capacity calculation of the inter-column slabs of flat slab frame system is developed by a kinematic way based on the ultimate equilibrium method. The basis of the study is the kinematic method of the limit equilibrium method and its application to calculate the load-bearing capacity of the inter-column slab in flat slab structural system, as well as to select the area of the working reinforcement. Attention is also paid to establishing the location of the lines of plastic hinges formation.