Improvement In Bearing Capacity Research Articles

Design of ultralight multifunctional sandwich structure with n-h hybrid core for integrated sound absorption and load-bearing capacity

Multifunctionality has become an important evaluating index for structural design because engineering applications in complicated environment call for multifunctional and ultralight structures. With this in mind, this paper proposes a novel ultralight multifunctional micro-perforated sandwich structure with N-H type hybrid cores, which demonstrates superior sound absorption across a wide frequency range, while also achieving good load-bearing capacity. An analytical model is established to calculate the sound absorption coefficient, which is then validated through numerical simulation and experimental measurements. Furthermore, the underlying physical mechanisms for the satisfactory sound absorption are explored. The influences of specific parameters on the broadband sound absorption performance of the proposed structure are quantitatively demonstrated through systematic parameter studies. Additionally, in order to demonstrate the preeminent multifunctional attributes of the proposed structure, a numerical simulation method is employed to evaluate its out-of-plane compression properties. Compared to other micro-perforated sandwiches, the proposed structure exhibits an improvement in load bearing capacity. A radar chart is also created to display the advantages of the proposed micro-perforated sandwich structure over others. Overall, the proposed ultralight sandwich structure with N-H type hybrid cores shows great significance for engineering applications that demand high comprehensive performances owing to its multifunctionality.

Experimental study on the treatment of deep miscellaneous fill foundation in Xinjiang by vibrating rod compaction method

Currently, the treatment of miscellaneous fill foundations, composed of a mixture of domestic garbage, construction solid waste, and natural soil, presents a significant challenge in urban peripheral engineering construction. This paper discusses the application of vibrating rod compaction technology for foundation treatment in Xinjiang. It evaluates the effectiveness of cross-section vibrating rod compaction equipment in reinforcing fine-grained miscellaneous fill foundations. The study analyzes the impact of construction disturbances caused by the insertion of the vibrating rod, monitoring horizontal stresses at various depths. Both laboratory and field tests show significant improvements: soil dry density increased by 8% to 18%, porosity decreased by 10% to 23%, compression modulus increased by 22% to 246%, and compression coefficient decreased by 8% to 70%. Additionally, cohesion (C) and angle of friction (ɸ) saw increases ranging from 7 to 38% and 3% to 25%, respectively. Below a depth of 3 m, cone tip resistance exceeded 10 MPa, and sidewall friction resistance increased to over 100 kPa, surpassing pre-treatment values. The standard penetration test results doubled stroke length compared to pre-treatment, indicating a substantial improvement in foundation bearing capacity. Surface wave tests before and after treatment showed a 15% increase in wave velocity, reflecting a more compact soil structure. The vibrating rod compaction method is innovative, energy-efficient, environmentally friendly, and economically beneficial, holding great potential for future miscellaneous fill treatments.

Geosynthetic stabilization of road pavements, railroads, and airfields

Geosynthetics provide sustainable alternatives for enhanced performance, durability and cost-effectiveness of road pavements, railways, and airfields. Even when the same geosynthetic products are used for constructing these different transportation facilities, an optimal approach is needed to match the properties of soils or unbound aggregate geomaterials and the geosynthetic products to establish an effective mechanical stabilization. This Proctor lecture keynote paper presents the state-of-the-practice on the transportation applications of geosynthetics, design methods, and the recent research findings on geosynthetics used in road and airfield pavements and ballasted railway tracks. The paper introduces first the transportation applications of commonly used geosynthetic products, i.e., geogrids, geotextiles, and geocells, with special emphases to subgrade restraint and unbound aggregate stabilization applications and discusses in detail the related unpaved and paved design procedures. Next, the focus is directed towards establishing a better understanding of geosynthetic mechanisms governing stabilization applications. To summarize, this keynote paper reports on two decades of developments and research findings at the University of Illinois and elsewhere on the topic of geosynthetic stabilization using the latest technologies to quantify the stiffness enhancement in the vicinity of a geosynthetic material via the bearing capacity improvement and lateral restraint mechanisms. Recent research at the University of Illinois focused on the successful use of bender element shear wave transducer technology is discussed in detail with several examples given related to the laboratory and field efforts of unbound aggregate base and railroad ballast geosynthetic stabilization including full-scale instrumentation of stabilization geosynthetics used in actual road and airfield pavements constructed in the United States.

Geogrid reinforcement for improving bearing capacity and stability of square foundations

Abstract Shallow foundations are often the most economical option for building support, as they distribute structural weight to soil layers, require minimal earthwork, and do not necessitate specialized machinery. The most common type of soil in the city of Karbala is sandy soil. It is granular and loose by nature which has a relatively low bearing capacity. According to previous studies, the soil weakness is one of the problems with shallow foundation construction. Thus, the aim of this study is to improve the properties of the soil using geogrid reinforcement. Three critical parameters are examined, including depth, size, and number of geogrid layers in the soil reinforcement process to increase bearing capacity and decrease soil settling. The effect of geogrid depth (u) was studied by considering four depth ratios (u/B = 0.5, 1.0, 1.5, and 2.0) in order to determine the ideal depth of the geogrid layer, where (B) refers to the width of the footings. The results indicated that a decrease in depth ratio significantly increased the bearing capacity of footings built on reinforced soil layers compared to those built on natural soil, and the settlement reduction ratio (SRR) also increased. The size of the geogrid layer (i.e., width of the geogrid layer (b) was evaluated by evaluating four size ratios (b/B = 1.5, 3.0, 4.5, and 6.0). With an increasing size ratio of the geogrid layer, the bearing capacity ratio (BRC) was significantly improved. Additionally, the study examined the optimal number of geogrid layers, focusing on single and multiple layers with N = 1, 2, 3, and 4. The results showed a higher BRC for footings on reinforced soil layers, as well as a significant rise in SRR with an increase in the number of geogrid layers. Finally, it was concluded that the optimal depth ratio was u/B = 0.5, the size ratio was b/B = 4.5, and reinforced with three geogrid layers, which provided the highest bearing capacity and SRR. The experimental test results were verified by comparing them with those calculated using theoretically developed models. The variation between the experimental and theoretical results is reasonable, confirming that the experimental testing results exhibit a high degree of accuracy.

Research on seismic performance of replaceable prefabricated RC beam-column joints

Based on the seismic design philosophy of recoverable functionality, this paper proposed a prefabricated concrete beam-column joint utilizing replaceable friction energy dissipation artificial plastic hinges (FAPH) as connecting devices. The connecting device comprised a pair of lugs and high-strength pins. This study analyzed the failure modes and hysteresis characteristics through cyclic loading tests performed on the precast beam-column joints. The results showed that the FAPH had a high peak capacity. However, the yield load was low, which reduced the energy-dissipation capacity of joints at the early stage. Therefore, lateral energy dissipation steel plates (EDPs) were added on both sides of the PAPH to improve bearing capacity. Then, utilizing ABAQUS finite element software, the mechanical behaviors of the optimized prefabricated joint such as the load-displacement curve, bearing capacity, ductility, and energy dissipation capacity were further analyzed. This paper also investigated the effect of the axial compression ratio, the friction coefficient, bolt preload, and connecting plate form of EDPs on the seismic capacity of the optimized joint. After optimization, the prefabricated joint exhibited a significant improvement in both yield capacity and cumulative energy dissipation, increasing by 47 % and 22 %, respectively. Additionally, there was a slight improvement in ductility. Increasing the axial compression ratio reduced the bearing capacity and ductility of prefabricated joints after the peak point. The specimen exhibited a significant increase in both peak capacity and cumulative energy dissipation as the friction coefficient increased. Additionally, the hysteresis curve of the joint became fuller with the increase in bolt preload. The connecting plates of EDPs mainly serve to transmit loads, and different forms of connecting plates had little effect on the bearing capacity and energy dissipation capacity of prefabricated joints.

Experimental Investigation of Bearing Capacity of Circular and Ring Footings on Geogrid-Reinforced Cohesionless Soils

Abstract This experimental investigation describes an extensive series of reduced laboratory scale tests, conducted on circular and ring footing models rested on a geogrid reinforced cohesionless soil. The study examined the impact of several factors at different relative sand densities, such as the inner to the outer diameter ratio of the ring footing, the number of geogrid reinforcements, the depth of the initial reinforcement, and the vertical spacing between the geogrids, as well as the geogrid stiffness. The results indicated that the optimum diameter ratio of ring footings resting on loose or medium-dense cohesionless soil is 0.40 at which the maximum bearing capacity is reached, leading in a cost-effective design of the footings, while for the dense soil, a diameter ratio of 0.45 is the optimal ratio. Also, the results indicated that the optimum number of reinforcement layers which after the bearing capacity improvement can be considered negligible is three layers for the circular footing and four layers for the ring footing model. To achieve the maximum increase in bearing capacity, the study identifies optimal values for the depth of the first geogrid reinforcement layer and the vertical spacing between reinforcements, which apply to circular and ring footing. While the stiffness of the reinforcement has a significant effect on the bearing capacity, this effect is not proportional.

Study on Pile Bearing Capacity Improvement in Soft Soil After Vacuum Consolidation

The main problem in developing property over soft soil is significant settlement due to the consolidation process. The soil settlement, which will occur gradually throughout the years, will disrupt existing infrastructures, in this case bridges. To mitigate this issue, the common method is by speeding up the consolidation. The consolidation process must be sped up to avoid the differential settlement problem at the bridge abutments. Due to the limited supply of fill material, a vacuum consolidation method is adopted. In this method, a Prefabricated Vertical Drain (PVD) is installed, and a vacuum is applied to impose pressure as preloading. Because of the consolidation process, theoretically, the effective stress of the consolidated soil increases, and the soil shear strength does as well. Increasing the shear strength of the soils will increases the pile capacity. However, the interesting question is how much the shear strength of the soil can increase and impacts the pile capacity. In this paper, the shear strength improvement of the consolidated soil and the effect on pile bearing capacity is evaluated. This study used a series of in-situ tests that were carried out before and after the vacuum consolidation. A pile loading test using the Pile Dynamic Analyzer (PDA) method was carried out to verify the pile bearing capacity improvements. From the comparison result, it is shown that the theoretical capacity of the piles after consolidation were close to the pile test results.

Flexural behavior of reinforced concrete beams strengthened with gradually prestressed near surface mounted carbon fiber-reinforced polymer strips under static and fatigue loading

The near surface mounted (NSM) carbon fiber-reinforced polymer (CFRP) strengthening technique, combined with gradually anchored prestressed technique, is utilized to delay the occurrence of concrete cover separation (CCS) and enhance the ductility of reinforced concrete beams. The load-carrying capacity of fully prestressed beams and gradually prestressed beams are investigated under both static and fatigue loading conditions. The study focused on the effect of gradient prestress on flexural behavior of strengthened beams, analyzed the failure mode, characteristic load, ductility, and stress distribution at CFRP-concrete interface under both prestress and load conditions. Results indicate that gradually prestressed beams outperform fully prestressed ones in restraining crack development, delaying yield of tensile reinforcement, improving bearing capacity and avoiding CCS failure. Bearing capacity was significantly increased by up to 35.48%, while ductility was greatly improved by 100.33% with ultimate deflection for gradually prestressed beams compared to fully prestressed ones. The fatigue life of gradually prestressed beams, which experienced a transition from CCS failure mode to fatigue fracture of tensile reinforcement, was significantly extended. Additionally, their ductility at failure was also greatly enhanced, thus confirming the effectiveness of gradually prestressed NSM CFRP strengthening technique.

A novel cylindrical mechanical metamaterial: Design, fabrication, and compressive properties

Mechanical metamaterials exhibit fascinating deformation characteristics and exceptional mechanical properties due to their distinctive unit cell structure and the repetitive development of these units. This research presents the design of a novel cylindrical metamaterial featuring a concave hexagonal structure. This design incorporates an auxetic structure within the outer circular tube in order to enhance radial shrinkage and improve bearing capacity and stability by leveraging the negative Poisson's ratio effect. The specimens were fabricated using 3D printing technology, and their mechanical properties and uniaxial compression deformation characteristics were subsequently investigated through experiments. Additionally, the accuracy of the finite element model was verified by comparing the simulated predictions with the experimental results. The specimens differ in terms of their internal and external structures. The external structures vary based on the combination of single cells and interlayers, resulting in three distinct types. The internal structures differ based on the angle of inward depression. The mechanical properties and deformation characteristics of specimens composed of different internal and external structures were analyzed, revealing that the cylindrical structure can possess adjustable stiffness, high stability, and compressive capacity.

Behavior of soil reinforced with micropiles

Abstract Soil investigation is very important to check the bearing capacity before constructing any structure. There are different types of soils that cause many problems for the structure in short and long term, which are known as problematic soils. A lot of researchers dealt with improvement and reinforcement of the problematic soils by physical and chemical treatments. The objective of this study is reinforcing the problematic soil with micropiles with different depths and different configurations. In this study, two types of soils, soft clay and loose sand, were used to study the effect of adding micropiles of different depths and different configurations to investigate the best improvement of bearing capacity for shallow foundations on these soils. The results showed that reinforcing the natural soil with micropiles could improve the pressure carrying capacity of the problematic soils. When the design width is changed from under foundation alone to under foundation and 2B width, the soil reinforced with 2B depth of micropiles can raise the soil’s load carrying capacity by 45 to 65% when compared to untreated soil. Just 7% more bearing capacity may be achieved by increasing the depth of the micropiles from 2B to 3B (where B is the footing width); as a result, going deeper than 2B is not advantageous. Additionally, the bearing capacity of the micropiles increases by only 3% when the breadth of the configuration is increased from 1B to 2B; so, wider configurations than 1B are invalid.

An asymmetric stabilizer layer structure of REBCO superconducting tapes for resistive superconducting fault current limiters

Used in resistive superconducting fault current limiters (R-SFCLs), REBCO tapes are required to have both large current limiting resistance and high over-current bearing capacity. The contradiction between high resistance and large over-current is the main difficulty in the design of REBCO-tape structure for R-SFCLs. In this paper, an asymmetric stabilizer layer structure of REBCO tapes has been proposed, fabricated and tested for R-SFCLs. Comparing to traditional tapes with a symmetric stabilizer structure, the REBCO tape with new structure showed a 59 % improvement in over-current bearing capacity: the peak current increased from 1020 A to 1620 A while keeping the same total resistance. Simulation calculation on the current distributions in every layer showed that the asymmetric structure is superior to the symmetric structure.

Experimental Study on the Seismic Performance of Brick Walls Strengthened by Small-Spaced Reinforced-Concrete–Masonry Composite Columns

Through low-cycle reciprocating tests on 11 masonry wall specimens strengthened using reinforced-concrete–masonry composite columns, the effects of the position of the composite column, height-to-width ratio, column reinforcement ratio, and axial load ratio on their load-carrying capacity, stiffness, ductility, and energy dissipation capacity were investigated. It was experimentally found that, by strengthening brick walls with RC–masonry composite columns, the concrete and masonry parts can work together effectively, the failure mode shifts from shear to flexural failure, and the strengthened walls exhibit improved bearing capacity, ductility, and energy dissipation performance compared to unstrengthened masonry walls. It is suggested the composite columns can be placed at the ends of the wall if a strengthening measure is required. For walls with height-to-width ratios greater than 1, placing composite columns in the middle of a wall has little effect on the bearing capacity and stiffness of the wall but can improve the ductility of the wall. The height-to-width ratio is a primary factor influencing the structural performance of masonry walls strengthened using composite columns. A smaller height-to-width ratio leads to higher load-carrying capacity and stiffness but may result in reduced ductility. In comparison, the impact of the column reinforcement ratio and axial load ratio is relatively weaker. The flexural capacity of the masonry wall after strengthening can be obtained using the calculation method for concrete members subjected to a combined action of flexure and compression, in which the compressive strength of the masonry is considered.

Pile Driving and the Setup Effect and Underlying Mechanism for Different Pile Types in Calcareous Sand Foundations

The mechanical response and deformation characteristics in calcareous sand foundations during pile driving and setup were studied using model tests combined with the technical methods of tactile pressure sensors and close-range photogrammetry. Different types of piles were considered, including a pipe pile, square pile and semi-closed steel pipe pile. The test results show that during pile driving, the pile tip resistance of different piles increases with an increase in the pile insertion depth, and an obvious fluctuation is also obtained due to the particle breakage of the calcareous sand and energy dissipation. Different degrees of particle breakage generated by different type piles make the internal stress variations different, as with the pile tip resistance. The pile tip resistance of model pile A, which simulates a pipe pile, is the highest, followed by model pile B, the simulated square pile. Model pile C, which simulates a semi-closed steel pipe pile, has the smallest pile tip resistance because its particle breakage is the most obvious and the pile tip energy cannot be continuously accumulated. The induced deformation such as sag or uplift on the surface and the associated influence range for the calcareous sand foundation are the smallest for model pile C, followed by model pile B and then model pile A. Model pile A has the most obvious pile driving effect. During the pile setup process after piling, the increase in the total internal stress of model pile B is the largest, and the improvement of the potential bearing capacity is the most obvious, followed by model pile A and model pile C. During the pile setup, the induced uplift deformation in pile driving is recovered and the potential bearing capacity increases due the redistribution and uniformity of the vertical and radial stress distributions in the calcareous sand foundation. Considering the potential bearing capacity of different model piles, the influence range of pile driving, foundation deformation and the pile setup effect, it is suggested to use a pointed square pile corresponding to model pile B in pile engineering in calcareous sand foundations.

The flexural performance of vertical steel-plate-reinforced bamboo scrimber beams

ABSTRACT Since the elastic modulus of bamboo scrimber is low relative to their strength, the design of bamboo scrimber beams is often restricted by their deformation. Therefore, this study proposes vertical steel plate-reinforced bamboo scrimber (PRBS) beams to improve the stiffness of bamboo scrimber beams more effectively while improving bearing capacity, thereby increasing the span and expanding the application scope of bamboo scrimber beams. To study the mechanical properties of PRBS beams, flexural loading tests on 21 beams were performed under 7 working conditions, and the effects of different thicknesses, opening ratios, and arrangements of built-in steel plates on the flexural performance of PRBS beams were studied. The results showed that the PRBS beams have two ultimate failure modes: tensile failure of the beam bottom and lateral buckling of the beam. Compared with Reference beams, PRBS beams with solid steel plate exhibit 45–51% higher bearing capacity and 52–104% higher stiffness, and PRBS beams with perforated steel plate exhibit 22–33% higher bearing capacity and 35–48% higher stiffness. In addition, a theoretical analysis was conducted on the flexural bearing capacity of PRBS beams based on the tri-linear constitutive model.

Rock bolts under cyclic loading: Mechanical performance and damage assessment by acoustic emissions

Rock bolt support is one of the key methods to maintain the stability of underground space. The durability of the rock bolt can be weakened by cyclic loading, resulting in premature failure of the underground structures. A comprehensive understanding of the performance of the bolting system under cyclic loading is essential to assess the safety of the bolting system and underground structures. In this context, this study investigated the mechanical performance of rock bolts installed in simulated soft and medium hard rock and subjected to cyclic loading. The Acoustic Emission (AE) technique was used to monitor internal damage to the bolt system under different loading conditions. A cumulative AE energy slope method has been proposed to determine the onset of the macro crack formation stage. The rock bolt demonstrated an extended fatigue life in soft rock, but its condition worsened when implanted in medium hard rock. The cyclic loading resulted in a slight improvement in the load bearing capacity of the soft rock bolt system and a significant deterioration in the medium hard rock bolt counterpart. The main fatigue failure modes of the rock bolt systems were splitting and shear failure of the surrounding rock, and debonding of the interface. Increasing the amplitude of the cyclic loading reduced the macro crack initiation cycle for both rock bolt systems, whereas increasing the frequency had different effects. The damage variable increased with frequency and amplitude for both rock bolt systems. The toughness of the soft rock bolt degraded during cyclic loading, while the high frequency cyclic loading did not modify the toughness of the medium hard rock bolt.

Review of Subgrade Soil Stabilised with Natural and Synthetic Fibres

Subgrade soil is an essential component in the design of road structures as it provides lateral support to the roadway. One of the main reasons for pavement failure is subgrade settlement, which leads to a loss of subgrade strength. If the mechanical properties of subsoils are lower than required, a soil stabilisation method may be an option to improve the soil properties of the weak subsoil. Soil stabilisation is one of the techniques for improving poor subsoil, which results in significant improvement in tensile strength, shear strength and bearing capacity of subsoil. Soil stabilisation can be broadly divided into four types: thermal, electrical, mechanical, and chemical. The most common method of improving the physical and mechanical properties of soils is stabilisation with binders such as cement and lime. However, soil stabilisation with conventional methods using cement and lime has become uneconomical in recent years, so an alternative such as fibres may be sought. This review provides a comprehensive comparison of the effectiveness of natural fibres and synthetic fibres in stabilising subgrade soils.

Utilization of Waste Aggregate for Aggregate Construction for Improvement of Soil Bearing Capacity

Soil bearing capacity is one of the important elements when designing the foundation, bridges, and embankment. The soil bearing capacity needs to be improved due to the weak soil such as clayey silt or silty clay soil that was encountered at the construction site. There are many stabilizations method such as bio treatment of the subgrade, chemical stabilization method, chemical grouting or injection systems, aggregates, or reuse of the waste materials, geosynthetic reinforced embankment and vibro compaction. One of the most common chemical stabilization methods is by using additives to improve soil strength. There are a few wastes material that can be used for strengthening clay soil which is more economic and environmentally friendly. The objective of this research is to improve the soil engineering parameters and bearing capacity using Recycled Waste Aggregates (RWA). In this study, soil samples will be added with different percentage weight of RWA and undergo a few series of laboratory experiments to study its behavior which will be sieve analysis, specific gravity, compaction, and California Bearing Ratio (CBR). The optimization of the percentage of recycled concrete aggregates can be determined from the simulation method. For bearing capacity value, the increase of bearing capacity greatly increases as the percentage of RCA increased and the optimum percentage of RCA is 15%. It concluded that the increasing value of RCA will improve the strength and soil subgrade structures. Recycled Concrete Aggregates have a really great potential material to be used in engineering.

Experimental study on the mechanical behavior of segmental joints of shield tunnels strengthened by a steel plate-UHPC composite

This research proposed a new technology to strengthen segment joints in shield tunnels based on steel plate-UHPC composite. In order to understand the strengthen mechanism of the steel plate-UHPC composite on the segmental joints, full-scale experiments were conducted to study the characteristics of the strengthened joints, including deformation, crack development, interface behavior, stress distribution, and the failure process. The results demonstrate that the deformation process under sagging moments involves four stages: elastic deformation, elastic–plastic deformation, debonding, and failure, whereas under hogging moments, the deformation can be summarized into three stages: elastic–plastic deformation, debonding, and failure. The use of UHPC strengthening facilitates more extensive crack development, and promotes uniform stress distribution within the concrete, with efficient utilization of material properties. The presence of anchor screws maintains a certain level of ductility after interface debonding. A significant improvement in the ultimate bearing capacity and flexural stiffness of specimens was observed with the use of steel plate-UHPC composite. The ultimate bearing capacity of initially strengthened specimens under sagging and hogging moments is increased by 503.3% and 72.2%, respectively, and the flexural stiffness is increased by 177.9% and 3803.2%, respectively. Moreover, the pre-damaged state of the strengthened specimen exhibits a significant increase in ultimate bearing capacity and flexural stiffness under a sagging moment, while remaining basically unchanged under a hogging moment.

Experimental study of partially encased bamboo scrimber columns under axial compression

ABSTRACT Both bamboo scrimber and section steel are extensively employed in the construction industry however bamboo scrimber as a large composite member, easily experiences buckling and splitting under compression. To solve the problem of insufficient bearing capacity, a partially encased bamboo scrimber (PEBS) column was developed in this paper, and the PEBS column consisted of an H-shaped steel member with two rectangular bamboo scrimber members placed inside the web and flanges, forming a partial buckling restraint configuration. The aim of this arrangement was to enhance the axial compressive performance of the bamboo scrimber members through partial lateral confinement. To investigate the influences of the composite effect and specimen size, a total of 45 specimens were tested under axial compression to analyse the failure modes, load–displacement relationships, and mechanical properties. The results revealed that the composite specimens ultimately failed owing to buckling and wedged splitting in the bamboo scrimber members. The partial buckling restraint exhibited a substantial improvement in axial bearing capacity through delaying the buckling of the H-shaped steel and failure of the inner bamboo scrimber, leading to a further enhancement in the safety stock. Finally, a calculation method was proposed to predict the ultimate bearing capacity of the PEBS column.

Compressive performance of bamboo scrimber and concrete-filled steel tube columns

The light and high strength bamboo scrimber was buried in the core of concrete-filled steel tube (CFST) to form bamboo scrimber and concrete-filled steel tube column (BCFST), which was expected to reduce the amount of concrete and weight in CFST and promote the use of bamboo scrimber. To investigate the influences of key design parameters on the compressive performance, namely bamboo scrimber dimension, design concrete strength, and diameter to thickness of steel tube, ninety BCFSTs and eighteen CFSTs specimens were tested under axial compression. According to the experimental results, the improvement of the BCFST bearing capacity resulted from the contribution of the inner sandwich concrete and the bamboo scrimber under the constraint from the steel tube. The ultimate load rose with the increase of the bamboo scrimber dimension, concrete strength, and steel tube thickness. Note that the increase range of ultimate load of BCFSTs is 3.9% higher than that of CFSTs by increasing the dimension of bamboo scrimber, with a maximum increase at 43.9%. The damage modes of BCFSTs can generally be categorized into local buckling failure mode and shear failure mode. In addition, owing to the different compactness between the bamboo scrimber and the concrete, the stress-strain curve of the C80 concrete characterized the strain hardening tendency rather than the strain softening tendency in the C50 concrete. According to the load-strain curves of the BCFSTs and the contribution of the composite actions between the three parts of the member to the load-carrying capacity, the characteristic points were defined. A calculation model for accurately predicting the ultimate capacity of BCFSTs was proposed by considering the boundary conditions for both non built-in and fully built-in bamboo scrimber in CFSTs.