Bending Moment Ratio Research Articles

Experimental and numerical study on behaviour of extended end-plate connections with Q960 steel at elevated temperature

This paper presented a series of tests to investigate the behaviour of the extended end-plate connection utilizing high strength Q960 steel. A total of 8 specimens were tested, including two under ambient temperature and three under high temperature. The results of the tests indicated that increasing the end-plate thickness from 8 mm to 12 mm significantly enhances the flexural capacity and initial rotational stiffness of the connections but reduces the critical temperature and ultimate rotation. In addition, a higher beam bending moment ratio was found to increase the ultimate rotation of the connections while having minimal impact on the critical temperature. Then, the finite element model of the connections was established to investigate the parametric effect, including column axial pressure ratio, beam bending moment ratio, and end-plate thickness on fire resistance. The numerical analysis indicated that increased column axial pressure ratio and end-plate thickness decreased fire endurance, critical temperature, and ultimate rotation of the connections. On the other hand, increasing the beam-bending moment ratio enhanced the ultimate rotation of the connections. Lastly, a rotation-temperature relationship model was proposed to accurately predict the temperature-rotation curve of high-strength steel Q960 end-plate connections, which was validated with experimental data.

Približni proračun kružnih AB stupova uz pomoć nomograma

Calculating the reinforcement of circular reinforced concrete (RC) columns involves not only the dual nonlinearity of the geometry and material but also the nonlinearity of the section width. Accurate solutions require iterative calculations. To develop the calculation method manually, the model column method was proposed to compute the second-order effect of the columns, and the strain method was used to calculate the ultimate strength of the sections analytically. The nomograms required to calculate the reinforcing steel content of the columns without iterations were obtained. The nomogram for calculating the section bearing capacity and reinforcing steel has three parameters (axial force, bending moment, and mechanical ratio of the reinforcing steel). Further, the nomogram for calculating the column bearing capacity and reinforcing steel has five parameters (axial force, bending moment, curvature, slenderness ratio, and mechanical ratio of the reinforcing steel), and the relationship between the five parameters can be expressed in a plan, which makes the application convenient. Finally, the calculation results of the nomograph were compared with those of the existing approximate calculation formulas and exact numerical methods, and the accuracy of the nomograms was verified.

Seismic vulnerability of shield tunnels in interbedded soil deposits: Case study of submarine tunnel in Shantou Bay

This paper presents a numerical approach for deriving seismic fragility curves for a submarine shield tunnel subjected to transverse ground shaking in interbedded soil deposits. To simulate the nonlinear behavior of soils, PM4Sand and HS-small constitutive models were adopted. In contrast, the closed-form elastic design method or elastic–plastic design method was used for modeling the shield tunnel lining considering the effect of joints on the seismic performance of structures. Fully coupled numerical analyses provided a satisfactory interpretation of the seismic responses of soil–structure systems considering the effects of groundwater level and soil–tunnel interaction. Subsequently, free-field peak ground acceleration was selected as the intensity measure. The ratio of maximum bending moment to capacity bending moment or permanent joint rotation of the tunnel lining was selected as the damage measure, combined with incremental dynamic analysis, a series of fragility curves were generated. In this study, one-dimensional equivalent-linear earthquake site response analysis was implemented to validate the nonlinear dynamic analysis under weak earthquakes. However, the analysis overestimates the amplitude periodic vibrations in interbedded soil deposits under strong earthquakes. Additionally, numerical results show that the examined tunnel is prone to slight or moderate damage under ground shaking, and its joints are more vulnerable to damage than its segments. The fragility curves constructed were compared with existing fragility curves, highlighting the significant effects of local soil profiles, groundwater conditions, soil–tunnel interaction, and segmental joints on the seismic vulnerability of shield tunnels in a submarine environment. The developed fragility functions contribute to the prediction of seismic damage to submarine shield tunnels of similar characteristics, enabling the rapid and efficient response of structures to disasters in ocean engineering.

CALCULATION MODEL OF A MULTI-STOREY REINFORCED CONCRETE FRAME WITH COMPLEXLY STRESSED BEAMS UNDER ACCIDENTAL IMPACT

A computational model is presented for determining deformations in complexly stressed beams of a structurally non-linear reinforced concrete frame in a transcendental state caused by a special emergency action in the form of a sudden removal of one of the structural elements. The determination of the stress-strain state after the formation of spatial cracks in the reinforced concrete elements of the frame was carried out using the calculated spatial section. At the same time, dynamic additional loads in the design section of the reinforced concrete frame element from a special impact are determined on an energy basis using the “bending moment-curvature” and “torque-angle of rotation” diagrams. The considered calculation algorithm includes the determination of forces in compressed concrete, longitudinal and transverse reinforcement for primary and secondary design schemes and verification of special limit state criteria. The results of a numerical analysis of the effect of cracking, the ratio of torque and bending moment on the stress state in transverse and longitudinal reinforcement and on the dissipative properties of a frame structural system are presented

Seismic Behavior Analysis of Recycled Aggregate Concrete-Filled Square Steel Tube Frames.

In this study, the seismic behavior of a recycled aggregate concrete-filled square steel tube (S-RACFST) frame under different design conditions was investigated. Based on previous studies, a finite element model for the seismic behavior of the S-RACFST frame was developed. Moreover, the axial compression ratio, beam-column line stiffness ratio, and yield bending moment ratio of the beam-column were regarded as the variation parameters. It was through these parameters that the seismic behavior of eight S-RACFST frame finite element specimens was discussed. The seismic behavior indexes, such as the hysteretic curve, ductility coefficient, energy dissipation coefficient, and stiffness degradation were obtained-which, in turn, revealed the influence law and the degree of the design parameters regarding seismic behavior. Moreover, the sensitivity of the various parameters with respect to the seismic behavior of the S-RACFST frame was evaluated via grey correlation analysis. The results show that the hysteretic curves of the specimens were fusiform and full with respect to the different parameters. Firstly, with the axial compression ratio increasing from 0.2 to 0.4, the ductility coefficient increased by 28.5%. In addition, the equivalent viscous damping coefficient of the specimen with the axial compression ratio of 0.4 was 17.9% higher than that of the specimen with the axial compression ratio of 0.2, which was 11.5% as well as that with an axial compression ratio of 0.3. Second, when the line stiffness ratio rises from 0.31 to 0.41, the specimens' bearing capacity and displacement ductility coefficient both get better. However, the displacement ductility coefficient gradually decreases when the line stiffness ratio is greater than 0.41. As a result, an optimal line stiffness ratio (0.41) thus exhibits good energy dissipation capacity. Thirdly, with the increase in the yield bending moment ratio from 0.10 to 0.31, the bearing capacity of the specimens improves. In addition, the positive and negative peak loads increased by 16.4% and 22.8%, respectively. Moreover, the ductility coefficients were all close to three, thus demonstrating good seismic behavior. The stiffness curve of the specimen with a large yield bending moment ratio with respect to the beam-column, is higher than those that possess a small beam-column yield moment ratio. In addition, the yield bending moment ratio of the beam-column possesses a significant influence on the seismic behavior of the S-RACFST frame. Furthermore, the yield bending moment ratio of the beam-column should be considered first in order to ensure the seismic behavior of the S-RACFST frame.

Flexural stiffness of recycled aggregate concrete beams under combined effect of load and steel corrosion

AbstractSince reinforced concrete members suffer from different types of loads during their service life, the steel bars embedded in reinforced concrete members can be easily corroded in chloride‐laden environment. To investigate the influence of combined effect of load and steel corrosion on the flexural stiffness of recycled aggregate concrete (RAC) beams, 12 RAC beams were prepared and tested. The effects of load level (i.e., the ratio of the load applied to beams to the ultimate load) and recycled coarse aggregate (RCA) replacement ratio (i.e., the ratio of RCAs to replace natural coarse aggregates) on the internal force arm coefficient of cracking cross‐section, the elastoplastic resistance moment coefficient of cross‐section, and the strain incongruity coefficient of corroded tensile steel bars were analyzed, and a calculation model for flexural stiffness of RAC beams under combined effect of load and steel corrosion was established. The results showed that when the ratio of bending moment to ultimate bending moment of the pure bending part of beams was within 0.55–0.80 and the average mass loss of tensile steel bars was less than 3.23%, 0.85 could be adopted as the internal force arm coefficient of cracking cross‐section. The elastoplastic resistance moment coefficient of cross‐section was approximately a constant when the corroded RAC beams were in the service stage, while it increased obviously with the load level. There was a strong linear relationship between strain incongruity coefficient and average mass loss of tensile steel bars during the service stage of corroded RAC beams, and the strain incongruity coefficient increased linearly with the load level. The calculated values of the model of flexural stiffness proposed in this paper were in reasonable agreement with the experimental values.

Numerical Simulation of a Barge Impact on Bridges with Different Configurations of Pile Group Foundations

Three-dimensional finite element dynamic analyses were conducted to evaluate the effect of barge impact of different speeds on the lateral performance of three pile group (PG) configurations (vertical, battered, mixed) in terms of peak lateral displacement, peak shear force, lateral stiffness of PGs, and contribution of piles and pier columns to the total resisting force. The concrete material was modeled using the Concrete Damaged Plasticity model. The clay behavior was described using the Modified Cam Clay model; while the sand was modeled using the Drucker Prager model. The results showed that the vertical PG had the lowest lateral stiffness; while the battered and mixed PGs had closely larger stiffness, which allowed the development of larger impact force and pile cap displacement in vertical PG as compared to other PGs. The results of shear force showed that the foundation contributed up to 82% of the total lateral force in battered and mixed PGs. The results also showed that in vertical PG, the first row had slightly higher percentage of lateral force compared to other rows; while in battered PG, the load percentage was evenly distributed between rows. A contrast performance was observed for mixed PG. The results of bending moment (BM) showed that the piles in vertical PG had notably higher BM than the piles in other PGs due to larger pile cap displacement. In all PGs, the piles in the edge column had higher BM ratio, with the leading row (L) had the highest BM ratio (69–72%) in all PGs.

Model Test Study of the Synergistic Interaction between New and Existing Components of Sheet Pile Walls

New and existing components of retaining structures are often combined in the width section. When combining the design and use requirements of the existing and new structures, the synergistic interactions between the existing and new structures and the design and working conditions require clarification. In conjunction with an actual project, a sheet pile wall consisting of existing and new components is proposed to retain an embankment. Indoor model tests were carried out to simulate the excavation and compaction and investigate changes in earth pressure, pile bending moment, shear force, and load-sharing ratio of the new and existing sheet pile walls at different stages. The results show that the earth pressure of the cantilever section of the existing and new piles increases with an increase in the fill volume or the upper uniform load. An inflection point is observed in the earth pressure curve halfway between the pile top and the ground due to sudden changes in the pile and soil stiffness. The bending moment of the new and existing piles increases and decreases with the distance from the top of the pile under different working conditions, and the maximum bending moment occurred at 0.485 and 0.9 m from the bottom of the existing pile and the bottom of the new pile, respectively. The lateral displacement of the new and existing piles decreases with the distance from the top of the pile. Due to the adjustment of the structural force in the cantilever section and the soil reaction force in front of the pile, the displacement curves of the new and existing piles are similar in the cantilever section. The displacement in the anchored section is initially larger for the existing pile than for the new pile but then becomes similar for both piles. In working condition 5, the top displacement of the existing pile was 6.531 mm, exceeding the control value (5.6 mm). The earth-pressure-sharing ratio of the existing pile decreases with an increase in the width of the filling material or the load. When the load was applied, the earth-pressure-sharing ratio of the existing pile was 0.451, indicating that the structural design of the combined sheet pile wall is reasonable.

The Transverse Bearing Characteristics of the Pile Foundation in a Calcareous Sand Area.

Reviewing literature revealed that the studies on the bearing characteristics of pile foundations mainly focuses on clay, ordinary sand, loess, saline soil, and other areas. However, few studies on the bearing characteristics of the pile foundation in calcareous sand were conducted. Besides, existing traditional studies ignored the variation of soil compression modulus with depth, and the effect of void ratio on the transverse bearing characteristics of the pile foundation in a calcareous sand area were not well understood. In response of these problems, this study conducted a theoretical investigation on the transverse bearing characteristics of the pile foundation in a calcareous sand area. The transverse bearing characteristics of the pile foundation were derived based on the Pasternak foundation model and the Winkler foundation model, incorporating the heterogeneous distribution of compressive modulus with buried depth. The calculation results of the Pasternak foundation model are closer to the observed results than the Winkler foundation model. Therefore, the following research on the transverse bearing characteristics of the pile foundation in the calcareous sand area adopts the Pasternak foundation model. Then, the effects of the pile length, pile diameter, pile elastic modulus, horizontal load, bending moment, and void ratio on the transverse bearing characteristics of the pile foundation in a calcareous sand area were thoroughly analyzed. Furthermore, the difference between the transverse bearing characteristics of the pile foundation in a calcareous sand area and a quartz sand area was discussed. Results show that the horizontal displacement of the pile top in a calcareous sand area is greater than the quartz sand area under the same conditions.

Theoretical analysis of the mechanical behavior of double-ring joints under pure bending, bending-shear and eccentric loading conditions

Taking double-ring joint as research object, the mechanical performances under pure bending, bending-shear and eccentric loading conditions of the joints were studied in this paper. Double-ring joints with different structural parameters were analyzed using finite element analysis and theoretical derivation methods and combined with experimental results. The following conclusions were obtained: 1) under the pure bending condition, the spring model of the double-ring joint was established, and the theoretical calculation formulas of the ultimate bearing capacity and initial rotational stiffness were derived; 2) under the bending-shear condition, the accuracy of finite element analysis models was verified by comparing the numerical with experimental results. The mechanical properties of double-ring joints under the bending-shear condition were similar to those under the pure bending condition; 3) based on the full-section plasticity criterion, the relationship between ultimate bending moment ratio η0N and axial force eccentricity δ was derived. With the exponential function for nonlinear fitting, the relationship between initial rotational stiffness ratio ξ0N and axial force eccentricity δ was derived.

Results of experimental studies of high-strength fiber reinforced concrete beams with round cross-sections under combined bending and torsion

The aim of the work - experimental investigation on crack propagation and deformation in high-strength fiber reinforced concrete beams with round cross-sections under combined bending and torsion for the development of practical methods of crack resistance, deformation and strength analysis of such structures, and also for the accumulation of new experimental data on resistance under combined loading. Method is experimental-theoretical. Results. Deflection plots and force-deformation relationships for high-strength fiber reinforced concrete beams with round cross-sections under combined bending and torsion are determined experimentally. Principal deformations in terms of elongation and compression of concrete for the experimental beam structures with high torsion to bending moment ratio are determined. It is established that for high-strength fiber reinforced concrete structures of circular cross-section, generally, development of one-two discrete cracks is observed, therefore the circular shape of the cross-section slightly reduces the concentration defined by the material structure of high-strength concrete. On the basis of the conducted investigation on high-strength fiber reinforced concrete structures with circular sections, new experimental data on the combined stress-strain state in the studied areas of resistance is obtained, such as: values of generalized cracking, and failure, load, its level relative to the ultimate load; distance between the cracks at different stages of crack propagation; crack widths at principal reinforcement axis level, at a double diameter distance from the principal rebar axes and also along the entire crack profile at various stages of loading; coordinates of nonplanar crack formations; patterns of crack formation, development and opening in reinforced concrete structures under combined bending and torsion.

Behavior of Strengthened RC Beams with CFRP Sheets under Combined Bending and Torsion

The experimental investigations were carried out to study the behavior of reinforced concrete beams strengthened by CFRP sheets under different loading conditions (pure bending, combined bending and torsion and pure torsion). The experimental work included testing twenty RC beams of the rectangular cross-section of dimensions of 160×240 mm and of 2600 mm length with an area of the ordinary reinforcement being kept constant for all beams. Two parameters were taken into consideration (Twisting to bending moment ratio (T/M) and CFRP strengthening pattern). The tested beams are divided into five groups. Each group consists of four beams; the first beam is without CFRP strengthening, the other three are strengthened with CFRP sheets of different arrangements (U-stirrups, U-stirrups and longitudinal CFRP sheets in the bottom and Full U- stirrups wrapping). Each beam is loaded to a different loading conditions (pure bending, T/M = 0.5, T/M = 1.0, T/M = 2.0 and pure torsion). The CFRP sheets were attached externally to the beam. Test results were analyzed based on the influence of CFRP on the ultimate load, vertical mid-span deflection and failure modes. In the experimental work, it was found that all strengthening patterns of CFRP sheets exhibited a significant increase in ultimate strength. This increase reached up to 78.9% for tested beams, when the beam strengthened in the form of full U- stirrups wrapping pattern for T/M = 0.5. In this study, it is observed that the use of external CFRP sheets attached to the tension sides of beams (U-stirrups and longitudinal CFRP in the bottom) could enhance the ultimate load capacity by 32.7% over the capacity of the unstrengthen control beam for T/M = 1.0.

Numerical Investigations on Behavior of Strengthened RC Beams with CFRP under Combined Bending and Torsion

The numerical investigations were carried out to study the behavior of reinforced concrete beams strengthened by CFRP under different loading conditions (pure bending and combined bending and torsion). The numerical work included analysis of eight experimentally tested beams of rectangular cross-section dimensions of (160×240) mm and (2600) mm length keeping the area of the ordinary reinforcement constant for all beams. The following parameters were taken into consideration, twisting to bending moment ratio (T/M) and CFRP strengthening arrangement. The analyzed beams are divided into four groups. Each group consists of two beams; the first beam is without CFRP strengthening, the other beam is strengthened with CFRP. Each beam is loaded to a different loading conditions (pure bending, T/M=0.5, T/M=1.0, T/M=2.0). The CFRP sheets were attached externally to the beam. Analysis results were analyzed based on influence of CFRP on ultimate load and vertical mid-span deflection. According to the numerical study, it was found that all strengthening arrangements of CFRP sheets exhibited a significant increase in ultimate strength. The three-dimensional (3D) finite element model (FEM) utilized in present work is capable to simulate the behavior of externally strengthened reinforced concrete beams by CFRP. Full bond connections (no slip) are assumed between the CFRP sheets and surface of concrete. The comparison between the numerical and the experimental results declared the validity of the numerical analysis where the range of the (Pexp./PANSYS) ratio in ultimate load was from 0.847 to 1.157. The general behavior of the (FEM) shows good agreement with the test results from the experimentally tested beams.

The weaken technique of bending moment for support beam of internal climb tower

This paper develops a new analysis method to weaken bending moment at the end of support beam of the inner climbing tower crane. Firstly, the equivalent length of the variable cross-section beam is calculated according to the principle which the angular displacement of the variable cross-section beam is equal to that of the equal cross-section beam under the action of the unit bending moment. Then, the deformation of the variable cross-section can be calculated by using the calculation formula of the equal cross-section beam. Finally, Graphic multiplication is used to solve the stepped variable cross-section statically determinate beam and the function relation between bending moment and inertia moment ratio and variable cross-section length ratio is obtained by MATLAB. It is of great significance to the thin-walled supporting and protection by using the function between the bending moment and the parameter to determine the optimal supporting main beam.

Seismic vulnerability of circular tunnels in soft soil deposits: The case of Shanghai metropolitan system

This paper aims at the vulnerability assessment of circular tunnels in soft soil deposits of the metropolitan subway system of Shanghai, accounting for the effects of soil-structure-interaction, local soil conditions and tunnel burial depth. The study focuses on the seismic vulnerability in the transversal direction. A suite of twelve earthquake records is selected and scaled from 0.1 g to 1.0 g to perform non-linear incremental dynamic analysis (IDA), and thus to assess the tunnel response under increasing levels of ground shaking intensity. A visco-elasto-plastic model with Mohr-Coulomb yield criterion is adopted to capture the non-linear behaviour of soil deposits under the seismic excitation. Fragility curves are constructed as a function of free-field peak ground acceleration (PGA) and peak ground velocity (PGV) considering the main sources of uncertainties, with the damage measure (DM) being defined in terms of acting over capacity bending moment ratio of the tunnel lining. The derived fragility curves are compared with existing empirical and analytical ones. Furthermore, vulnerability curves are generated from the derived fragility curves. The significant role of local soil conditions and tunnel burial depth in the vulnerability of tunnels in soft and deep alluvial deposits is highlighted. The proposed fragility and vulnerability functions may be particularly used for the risk analysis of circular tunnels in soft deposits (Vs30 < 200 m/s) exposed to seismically-induced transient ground deformations in the transverse direction.

Effect of Earthquakes over Time on the Geogrid-Pile Foundation System in Loose Sand

Researchers and engineers have developed several means to enhance the dynamic lateral stability of civil engineering structures, such as geosynthetic reinforced earth retaining structures to resist excessive earthquake shaking. There is, however, as yet little information about using geogrids with pile foundations under earthquake loadings. This study thus linked a single embedded pile in loose sandy soil with a geogrid, with the system then subjected to two different seismic waves.The laboratory tests were carried out on single pile with a length to diameter ratio of 25 in poorly graded soil (SP) with a relative density of 30%. The geogrid used in the research was Nelton CE121 geogrid (700×700 mm), which was connected with the pile at a depth of 1/8 of the pile length. The model was then subjected to replications of both the Ali Al Gharbi and Halabjah earthquakes, which hit Iraq in 2014 and 2017, respectively.It was found that using geogrid with pile foundation reduced the settlement in the pile by about 50% and 90% for the Halabjah and Ali Al Gharbi earthquake forces, respectively. The maximum bending moment was also reduced, with the bending moment ratio at the pile surface for the Halabjah and Ali Al Gharbi earthquakes being 70% and 50% respectively. The settlement ratio increases as magnitude of earthquake decreases.

Mechanical behavior of high-strength bolts in T-stubs based on moment distribution

A T-stub is a component comprising a T-section with two bolts attached to its flange. It can be used to analyze the mechanical behavior of high-strength bolts in tension. In this study, the mechanical behavior of bolts was assessed via six static tests and 17 finite element analysis models. The effects of the thickness of the flange, the length of the inner and outer flange, and the diameter of the bolt were studied. With the exception of outer flange length, the parameters significantly affected the bolt bending moment, yielding load, and T-stub failure mode. Both the tests and the finite element analyses indicated that when the bolts yielded, the bending stress could reach 13% to 45% of the total tensile stress in the samples. It is not advisable to design bolts without considering the effect of the bending moment. A stable bending moment distribution relationship was also found between the bolt and the outer flange. The bending moment of the joint, the bending moment ratio of the bolt to the joint, and the distance from the contact force center to the bolt center are also discussed. Lastly, a new T-stub connector model and calculation method were proposed and proven to be reliable. This method is based on the theory of moment distribution and does not require the prying force to be calculated.

Study on Parametric of Moving Amount of Unseating Prevention Devices for Highway Bridges

Taking a three-span continuous bridge as the research object, the nonlinear time history analysis method is adopted. The influence of the moving amount of the unseating prevention devices on the seismic performance of the bridge under different fortification intensity was studied, and the reasonable value of the moving amount of the unseating prevention devices was discussed. Research shows that, in the starting range of the unseating prevention devices, the smaller the moving volume of the unseating prevention devices, the higher the fortification intensity, the decrease amplitude in the relative displacement of the pier beam, the internal force of the unseating prevention devices and the ratio of bending moment at bottom of side piers to middle piers are all greater. The higher the fortification intensity of the bridge site, the value of the reasonable movement of the unseating prevention devices will have greater. When the acceleration peaks are 220cm/s2, 400cm/s2 and 620cm/s2, the reasonable value of the moving amount can respectively be 9cm, 11cm, and 15cm.

A quantitative analysis of the spatial effects of retaining structure for slender foundation pits

The methods for design of retaining structures of hollow slender foundation pits based on classical earth pressure theories such as Rankine’s and Coulomb’s theories have inevitably drawn fierce criticization for their incapable of considering spatial effects of the structures. Researches in understanding the spatial effects of retaining structures are still in initial qualitative analysis stages. In this paper, three spatial effect ratios including displacement ratio, earth pressure ratio and bending moment ratio of a retaining structure were defined for the sake of analyzing the spatial effects of retaining structures of hollow slender foundation pits. Nonlinear finite element analyses and laboratory model tests of retaining structures in sands were conducted. The spatial effect ratios and the relationships of additional earth pressures vs. wall displacements were obtained from the results of the finite element analyses and model tests, and they all shown significantly variation with the process of excavation, and show a strong tendency in their distribution at different positions. These results are distinct from that based on classical earth pressure theories in general rules, and of importance in developing new design methods that make use of the spatial effects in practice.

Behavior of large piled-raft foundation on clay soil

The piled-raft foundation is usually adopted to support the offshore structures. In the present study, a large piled-raft has been simulated numerically through 3-D finite element modeling. The objective of the present study was to investigate the effect of pile spacing, pile length, pile diameter and raft-soil stiffness ratio on the settlement, load-sharing, bending moments, and shear force behavior of large piled-raft foundation. The results indicated that with increase in pile spacing up to the 5 to 6 times of the pile diameter, both average settlement ratio and differential settlement ratio decreased effectively and thereafter it increased gradually. Raft with smaller raft-soil stiffness ratio and larger pile group to raft width ratio observed to be effective in decreasing the average settlement ratio. The load-sharing ratio decreased with increase in pile spacing whereas; it increased with increase in pile length. With increase in pile spacing, bending moment ratio increased and as the length of pile increased bending moment ratio decreased up to pile group to raft width ratio of 0.6 and thereafter it increased.