Search

In this paper, a new type of bamboo scrimber column embedded with steel bars (rebars) was proposed, and the compression performance was improved by pre-embedding rebars during the preparation of the columns. The effects of the slenderness ratio and the reinforcement ratio on the axial compression performance of reinforced bamboo scrimber columns were studied by axial compression tests on 28 specimens. The results showed that the increase in the slenderness ratio had a significant negative effect on the axial compression performance of the columns. When the slenderness ratio increased from 19.63 to 51.96, the failure mode changed from strength failure to buckling failure, and the maximum bearing capacity decreased by 43.03%. The axial compression performance of the reinforced bamboo scrimber columns did not significantly improve at a slenderness ratio of 19.63, but the opposite was true at slenderness ratios of 36.95 and 51.96. When the reinforcement ratio increased from 0% to 4.52%, the bearing capacity of those with a slenderness ratio of 51.96 increased by up to 16.99%, and the stiffness and ductility were also improved. Finally, based on existing specifications, two modification parameters, the overall elastic modulus Ec and the combined strength fcc, were introduced to establish a calculation method for the bearing capacity of the reinforced bamboo scrimber columns. The calculation results were compared with the test results, and the results showed that the proposed calculation models can more accurately predict the bearing capacity. [ABSTRACT FROM AUTHOR]

Bridges will inevitably experience structural damage during long-term operation, which will decrease their structural load bearing capacity and durability. The vibration characteristics of bridge structures can be used as evaluation indicators for accurately diagnosing their deterioration. This study aimed at developing a vibration testing method for identifying bridge deck damage that does not affect traffic and is easy to implement. The vibration tests on the in-service bridge revealed it was mainly subjected to vertical vibrations, with the accelerations in the vertical direction about twice those in the horizontal direction. Based on fast Fourier transform analysis, the dominant vertical vibration frequencies were 2.34 Hz, 4.10 Hz, 10.30 Hz, 14.45 Hz and 18.75 Hz. A series of 0.1–0.3 Hz bandpass filters were used with those frequencies at the centers for modal analysis. The experimental results were then compared to the finite element analysis results. This study proposed a vibration-based damage identification method based on the differences between the bridge deck and both main steel girders. The study confirmed the convenience and effectiveness of using underneath maintenance walkways for wireless vibration testing. [ABSTRACT FROM AUTHOR]

The primary goals of this research are to examine the structural appearance of a horizontally curved bridge to identify any damages within the bridge structure, examine its dynamic and static reactions below moving load and service load (load combination) using CSI-Bridge Ver. 25, and to compare the static results with allowable values in the standards to determine the structural state of the bridge. Considering the findings for the appearance inspection, static and dynamic analysis, the bridge's superstructure and substructure did not sustain any damage. The measured values of static responses, such as positive bending moment, negative bending moment, compression stress, vertical deflection, and tensile stress, were found to be below the allowable thresholds in the ASSHTO LRFD-Bridge 2017, implying that the structural stiffness, bearing capacity, and load resistance are adequate, and that downward vertical deflection and cracks are unlikely to occur with structural component parts of the bridge under these types of designed loads. Dynamic research revealed that the dynamic natural frequency was lower than the live load natural frequency, indicating that the bridge structure is in a prolonged state of vibrating due to moving loads. [ABSTRACT FROM AUTHOR]

In order to study the difference of bearing capacity between polypropylene fiber reinforced engineered cementitious composite ( PP-ECC) bridge pier and ordinary concrete bridge pier under compressive-bending load, the flexural performance of six PP-ECC bridge piers and two ordinary concrete bridge piers were studied by quasi-static test. Combined with the failure process of PP-ECC bridge pier, the characteristic points of compressive-bending failure of PP-ECC bridge pier were determined. Then, based on the simplified constitutive model of PP-ECC material, the theoretical cracking, yield and ultimate load formulas of PP-ECC bridge pier were derived. The characteristic parameters of the simplified PP-ECC constitutive model were determined by uniaxial tensile and uniaxial compression tests of PP-ECC materials. The calculation results were verified by the experimental results, and the differences of flexural bearing capacity and maximum deformation of piers under different axial compression ratios and PP-ECC zone heights were compared. The results show that after PP-ECC bridge pier is cracked, PP-ECC in the tensile zone still work, and cooperates with the tensile steel bar to participate in the section force. When PP-ECC bridge pier reaches the ultimate load, the crack develops steadily, and there is no large area of concrete spalling in the protective layer of ordinary concrete pier. The maximum deformation of PP-ECC bridge piers under ultimate load are larger than that of ordinary concrete piers, and the increase of axial compression ratio will reduce the deformation capacity of piers. Increasing the height of PP-ECC zone at a higher axial compression ratio, the flexural capacity of the pier increases by 8. 8%. When using the simplified constitutive model to calculate the flexural bearing capacity of PP-ECC bridge pier feature points, the calculation accuracy reaches 0. 86 - 1. 13, and the variance analysis value is small, which has good calculation accuracy. [ABSTRACT FROM AUTHOR]

Copyright of Transportation Science & Technolgy is the property of Transportation Science & Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Prestressed concrete box girders are commonly employed in the development of high-speed railway bridge constructions. The prestressed strands in the girder may corrode due to long-term chloride erosion, leading to the degradation of its flexural performance. To examine the flexural performance of corrosion-affected simply supported prestressed concrete box girders, eight T-shaped mock-up beams related to the girders used in the construction of high-speed railway bridges were manufactured utilizing similarity theory. Seven of the beams underwent electrochemical accelerated corrosion, and then each beam was subjected to failure under the four-point load test method. Measurements recorded and analyzed in detail during the loading process included the following: crack propagation, crack width at various loads, crack load, ultimate load, deflection, and concrete strain of the mid-span section. The results demonstrate that a corrosion rate of just 8.31% has a considerable impact on the structural integrity of the beams, as evidenced by a pronounced reduction in flexural cracks and a tendency towards reduced reinforcement failure. Furthermore, the corrosive process has a detrimental effect on mid-span deflection, ductility, and ultimate flexural bearing capacity, which could have significant implications for bridge safety. This study provides valuable insights for the assessment of flexural performance and the development of appropriate maintenance strategies for corroded simply supported box girders in high-speed railways. [ABSTRACT FROM AUTHOR]

With the increasing demand for the performance and design refinement of steel structures (including houses, bridges, and infrastructure), many structures have adopted ultimate bearing capacity in service. The design service lives of steel building structures are generally more than 50 years, and most of them contain bolted connections, which suffer from extreme conditions such as fire (high temperature) during service. When the structure contains defects or cracks and bolt holes, it is easy to produce stress concentration at the defect location, which leads to crack nucleation and crack propagation, reduces the bearing capacity of the structure, and causes the collapse of the structure and causes disasters. In the process of structural damage and crack propagation, the traditional method has some disadvantages, such as stress singularity, the mesh needing to be redivided, and the crack being restricted to mesh; however, the integral method of peridynamics (PD) can completely avoid these problems. Therefore, in this paper, the constitutive equation of PD in high temperature is derived according to the variation law of steel material properties when changed by temperature increase and peridynamics parameters; the damage and crack expansion characteristics of Q345 steel specimens with bolt holes and a central double-crack at 20 °C, 200 °C, 400 °C, and 600 °C were analyzed to clarify the structural damage and failure mechanism. This study is helpful for providing theoretical support for the design of high-temperature steel structures, improving the stability of the structure, and ensuring the bearing capacity of the structure and the safety of people's lives and property. [ABSTRACT FROM AUTHOR]

In recent years, there have been an increasing number of examples of using ultrahigh-performance concrete (UHPC) as a pavement layer to form an ultrahigh-performance concrete–normal concrete (UHPC–NC) composite structure to improve the bearing capacity of bridges. In order to study the flexural performance of this kind of structure, this research studied the flexural performance of UHPC–NC composite slabs, with UHPC in the compression zone, using experiments, numerical simulation, and theoretical analysis. The results showed the following. Firstly, after the UHPC–NC interface had been chiseled, there was no obvious slip between the two materials during the test, and the composite plate was always subjected to synergistic stress. Secondly, the composite slabs in the compression zone of the UHPC were all subjected to bending failure, and the cooperative working performance of each part under the bending load was good, indicating that the composite slab had a unique failure mode and a high bearing capacity. Thirdly, increasing the thickness of the UHPC significantly improved the flexural capacity of the composite plate, and the maximum increase was about 15%. Increasing the reinforcement ratio of the tensile steel rebars also had an increasing effect, with a maximum increase of about 181%. Finally, the proposed formula for calculating the flexural capacity of composite slabs with UHPC in the compression zone could accurately predict the bearing capacity of said slabs. The calculated results were in good agreement with the experimental values, and the error was small. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Nanchang University (Engineering & Technology) is the property of Nanchang University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As the bridge's structural component is directly subjected to vehicle loads, the stress performance of the bridge deck has a significant impact on the safety, durability, and driving comfort of the bridge. In order to improve the bending performance of the bridge deck in the negative moment zone, a new type of steel grating–UHPFRC composite bridge deck was proposed in this paper. Firstly, structural details and advantages of the new steel grating-UHPFRC composite bridge deck were introduced. Secondly, the finite element program ABAQUS was used to establish a refined solid finite element model of the new bridge deck. The mathematical program MATLAB (PYTHON) was also used to analyze the effects of the structural parameters on bending bearing capacity and put forward reasonable structural parameters of the new bridge deck, considering the technical and economic indexes. Thirdly, the simplified plasticity theory was applied to analyze the bending bearing capacity of the new bridge deck, and the corresponding formula for bending bearing capacity calculation was derived and verified by numerical model results. In addition, the cost–benefit analysis and environmental impact assessment of the new bridge deck were also conducted. The results show that the bending bearing capacity of the new bridge deck in the negative moment zone increases with the increase of the width of the bridge deck, the thickness of the wing plate, and the height of the web plate, with a trend of increasing and then decreasing when the horizontal inclination of the web plate decreases. The bridge deck width does not have a significant effect on improving the bearing capacity. The bearing capacity calculated by theoretical formulas is close to that calculated by numerical models and the maximum relative deviation is 9.1%. The new steel grating-UHPFRC composite bridge deck proposed in this paper is superior to conventional steel-UHPC composite bridge deck in terms of cost-benefit and environmental impact. [ABSTRACT FROM AUTHOR]

To ensure the long-term safety and stability of bridge pile foundations in permafrost regions, it is necessary to investigate the rheological effects on the pile tip and pile side bearing capacities. The creep characteristics of the pile-frozen soil interface are critical for determining the long-term stability of permafrost pile foundations. This study utilized a self-developed large stress-controlled shear apparatus to investigate the shear creep characteristics of the frozen silt-concrete interface, and examined the influence of freezing temperatures (−1, −2, and −5°C), contact surface roughness (0, 0.60, 0.75, and 1.15 mm), normal stress (50, 100, and 150 kPa), and shear stress on the creep characteristics of the contact surface. By incorporating the contact surface's creep behavior and development trends, we established a creep constitutive model for the frozen silt-concrete interface based on the Nishihara model, introducing nonlinear elements and a damage factor. The results revealed significant creep effects on the frozen silt-concrete interface under constant load, with creep displacement at approximately 2–15 times the instantaneous displacement and a failure creep displacement ranging from 6 to 8 mm. Under different experimental conditions, the creep characteristics of the frozen silt-concrete interface varied. A larger roughness, lower freezing temperatures, and higher normal stresses resulted in a longer sample attenuation creep time, a lower steady-state creep rate, higher long-term creep strength, and stronger creep stability. Building upon the Nishihara model, we considered the influence of shear stress and time on the viscoelastic viscosity coefficient and introduced a damage factor to the viscoplasticity. The improved model effectively described the entire creep process of the frozen silt-concrete interface. The results provide theoretical support for the interaction between pile and soil in permafrost regions. [ABSTRACT FROM AUTHOR]

To investigate the evolution of load-bearing characteristics of pre-stressed beams throughout their service life and to provide a basis for accurately assessing the actual working state of damaged pre-stressed concrete T-beams, destructive tests were conducted on full-scale pre-stressed concrete beams. Based on the measurement and analysis of beam deflection, strain, and crack development under various loading levels during the research tests, combined with the verification coefficient indicators specified in the codes, the verification coefficients of bridges at different stages of damage can be examined. The results indicate that the T-beams experience complete, incomplete linear, and non-linear stages during the destructive test process. In the complete linear elastic stage, both the deflection and bottom strain verification coefficients comply with the specifications, indicating a good structural load-bearing capacity no longer adheres to the code's requirements. In the non-linear stage, both coefficients exhibit a sharp increase, resulting in a further decrease in the structure's load-bearing capacity. According to the provisions of the current code, the beam can be in the incomplete linear stage when both values fall within the code's specified range. The strain verification coefficient sourced from the compression zone at the bottom of the flange is not recommended for assessing the bridge's load-bearing capacity. [ABSTRACT FROM AUTHOR]

The reliable anchorage of carbon fiber-reinforced polymer (CFRP) tendons is a critical issue influencing the stable bearing capacity of bridge cables. This study introduces a novel CFRP single-strand extrusion anchoring structure, where the strand is compressed at its end. By integrating this with internal cone filler wrapping, we create a CFRP multi-strand cable composite anchoring system. This innovative design not only minimizes the overall dimensions of the anchoring system but also significantly improves its anchoring efficiency coefficient. An axisymmetric model was developed using ANSYS finite element software. The radial stress distribution and anchorage efficiency coefficient in the anchorage zone of Φ7 CFRP bar and Φ13.6 extrusion die were analyzed with varying parameters, such as chamfering, outer diameter, and length of the extrusion sleeve, and were validated through static load anchorage tests. The results indicate that the highest anchoring efficiency is achieved when four extrusion sleeves with a chamfer angle of 5°, an outer diameter of Φ14.4, and a length of 15 mm are connected in series, reaching a coefficient of 61.04%. Furthermore, this study proposes an anchorage structure where multiple extrusion sleeves are connected in series and sequentially compressed to overcome the limitations of increasing anchorage length for enhancing the anchorage coefficient. The test results demonstrate that with equal total anchorage length, connecting four 15 mm extrusion sleeves in series enhances the anchorage efficiency coefficient by 24.98% compared to a single 60 mm extrusion sleeve structure. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Ordnance Equipment Engineering is the property of Chongqing University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper mainly introduces the emergency repair process for small- and medium-span bridges. The causes of deterioration were analysed by investigating old bridges. After comparison and selection of schemes, the scheme of beam replacement was confirmed using a lightweight steel ultra-high performance concrete (UHPC) composite beam as the superstructure. The main components of the calculations and the design are introduced in detail. Finally, through the load test of the bridge, it was shown that the lightweight steel-UHPC composite beam had good performance and met the requirements of Highway Level I bearing capacity. The lightweight steel-UHPC composite beam described in this paper has the characteristics of high strength, light weight, fast construction, excellent working performance, and remarkable social and economic benefits. It can be popularised and applied in the emergency repair of small- and medium-span bridges and new bridges. [ABSTRACT FROM AUTHOR]

This study proposes a new method to assess the bearing capacity of similar bridges while avoiding the disadvantages of costly static loading tests. First, we present a detailed evaluation of the bearing capacity for a repaired pre-stressed concrete continuous-beam bridge following a ship collision. We have developed a finite element model, modified it, and combined with two other methods to evaluate its bearing capacity. The first method proposed is the bridge design code-based method, where the bearing capacity is assessed using specified design parameters. The second is the field test-based method, where the bearing capacity is evaluated using field tests combined with structural appearance observation. Considering the relative merits of these two methods, a new and improved method for bearing capacity evaluation is proposed and implemented by combining the design code, finite element model, and field loading tests. The innovation and contribution of this paper lie in obtaining modal parameters through a convenient dynamic load test to predict the static behaviour of the bridge structure based on the modified finite element model. Based on the dynamic test results, the static behaviour of the bridge, predicted by the modified finite element analysis, and the appearance test data of the bridge structure, the bearing capacity of the bridge structure is evaluated. [ABSTRACT FROM AUTHOR]

Copyright of China Sciencepaper is the property of China Sciencepaper and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the present paper, an experimental study was conducted to determine the factors affecting the point bearing capacity of pile foundations constructed in dry and saturated sandy soils. Model piles were installed as reinforced concrete bored piles cast-in-situ. Model pile foundations of various geometries resting at different depths in homogeneous sand of different saturation degrees (%0-100) were loaded statically to failure. The test results showed that the bearing capacity of piles did not significantly affect by the loading rate. At most 10% difference was observed in pile bearing capacity when the loading rate was between 0.7 and 2.5 mm/min. Subsequently, the load bearing capacities of the piles were determined at a specified constant loading rate. The point and total capacities of the piles were measured separately in the experiments, then test results were compared with theoretical values. Pile point capacities provided from pile load tests are smaller than the theoretical values. The differences between experimental and theoretical results have been attributed to the Nq values. The Nq values not only dependent on the internal friction angle of the soil but also the saturation degree of the soil, the pile diameter, and the effective stress. Nq values decrease since the pile length/pile diameter ratio increases. [ABSTRACT FROM AUTHOR]

The orthotropic steel bridge deck (OSBD) has been widely used in recent decades, benefiting from its advantages of lightweight and easy assembly. However, the longitudinal and transversal stiffeners of OSBDs are connected to the top flange plate through dense welds, which will easily introduce fatigue cracks. Hence, the composite bridge deck (CBD) system was proposed, adding a concrete layer over a steel plate to increase the sectional stiffness of OSBDs and reduce the fatigue stress amplitude. Furthermore, some new materials with extraordinary properties such as ultra-high-performance concrete (UHPC) and engineering cementitious composites (ECC) were used to replace the normal concrete, to improve the bearing capacity and crack resistance of CBDs. In this review, four kinds of bridge deck systems with different structural types including OSBD, steel-concrete, steel-UHPC, and steel-ECC CBDs were discussed. The flexural performance of four systems under sagging and hogging moments was reviewed, and close attention was paid to the crack resistance of the CBD system. In addition, the shear connection used in the CBDs was concentrated, and the shear behavior of some connectors including studs, perforated rib (PBL), and modified clothoid (MCL) shape shear connectors was investigated. The CBD structure assembled by duplicate profile steel parts proposed recently was introduced and discussed. [ABSTRACT FROM AUTHOR]

This paper presents an easily installed improved perfobond connector (PBL) designed to reduce the shear concentration of PBL. The improvement of PBL lies in changing the straight penetrating rebar to the Z-type penetrating rebar. To study the shear performance of improved PBL, two PBL test specimens which contain straight penetrating rebar and six improved PBL test specimens which contain Z-type penetrating rebars were designed and fabricated, and push-out tests of these eight test specimens were carried out to investigate and compare the shear behavior of PBL. Additionally, Finite Element Analysis (FEA) models of the PBL specimens were established and validated against the test results. Through FEA, the effects of concrete grade, perforated plate's aperture, Z-type penetrating rebar's diameter, Z-type penetrating rebar's bending angle, and bending length on shear behaviors were discussed. The results indicate that (1) Compared with PBL specimens with straight penetrating rebars, Z-type penetrating rebar can significantly improve the shear resistance and shear stiffness of the specimens. This enhanced performance can be mainly attributed to the increased adhesion of the transverse rebar. (2) By comparing the load-slip curve, the slip of PBL test specimens which contain straight penetrating rebar increases rapidly and the bearing capacity decreases rapidly after concrete craking, while the bearing capacity of Z-type penetrating rebar specimens decreases first and then increases gradually, showing better ductility. (3) The stress of the PBL shear connector with Z-type penetrating rebar is more uniform than the PBL shear connector with straight penetrating rebar, and the overall deformation is more uniform. (4) The higher the concrete grade, the higher the shear bearing capacity and the better ductility of the new PBL. Increasing the aperture of the perforated plate or the diameter of the rebar has a very limited effect on the improvement of the shear capacity of PBL. Through the systematic analysis of the mechanical properties of Z-type penetrating rebar PBL specimen, the experimental reference is provided for improving the structure and design of new type PBL. [ABSTRACT FROM AUTHOR]

The analytical model for calculating the bearing capacity of a pile, presented in the commentary to STN 73 1002 - Pile Foundations, gives a recommendation to reduce the pile's length in the calculation of the shaft resistance. The recommendation is based on Caquot-Kérisel's theory. Especially in the case of embedded piles, reducing a pile's length in the calculation can cause the shaft friction of the embedded pile to be neglected, and the calculated resistance of the pile is thus significantly lower. The results of instrumented static load tests of embedded piles were analysed. The main aim of the study was to verify the validity of reducing the pile's length in the analytical calculation of the shaft resistance. The results of the static load tests analysed did not show any reduction in the shaft friction on the embedded part of the pile. In the form of a parametric study, the effect of reducing the pile's length in the calculation of shaft friction was analysed for different dimensions of embedded piles. [ABSTRACT FROM AUTHOR]

Pile foundations are vastly utilized in construction projects where their capacities (pile bearing capacity, PBC) should be determined in different stages of construction. A highly reliable and accurate prediction model can lead to many advantages, such as reducing the construction cost, shortening the construction timeline, and providing safety construction. Hence, the aim of this study is the developments of statistical and artificial intelligence (AI) models for predicting bearing capacities of 141 piles. At the preliminary of the study, features or inputs of this study to predict PBC were selected trough simple regression analysis. Then, this study presents different kernels of support vector machine (SVM) technique, i.e., the dot, the radial basis function (RBF), the polynomial, the neural, and the ANOVA to predict the PBC. The aforementioned models were evaluated by several performance indices and their results were compared using a simple ranking system. The results showed that the SVM-RBF model is able to achieve the highest coefficient of determination, R2 values which are 0.967 and 0.993 for training and testing stages, respectively. It is important to mention that a multiple regression model was also employed to predict PBC values. The other SVM kernels were provided a high degree of accuracy for estimating PBC, however, the SVM-RBF model is recommended to be used as a powerful, highly reliable, and simple solution for PBC prediction. [ABSTRACT FROM AUTHOR]

This study provides an equation of bearing capacity for a rectangular footing placed on dense sand overlying loose sand and subjected to inclined concentric loading using the limit equilibrium followed by projected area method. The parameters varied were thickness ratio (0.00 to 2.00) of the upper dense sand layer, embedment ratio (0 to 2), friction angle of upper dense (41° to 46°) sand and lower loose (31° to 36°) sand layer, and applied load inclination (0° to 30°) for the parametric study. The highest and lowest increase in the bearing capacity were observed for a friction angle combination of 46°-36° and 41°-31°, respectively, at different thickness ratios. The bearing capacity obtained from the proposed equation was approximately 4.97 and 10.5 times its initial value at embedment ratios of 1 and 2, respectively. Bearing capacity was reduced by 20.55%, 54.58% and 87.90% for load inclinations of 5°, 15°, and 30° for friction angles of upper dense and lower loose sand layer combinations of 46° and 36° and at a thickness ratio of 2. The bearing capacity obtained from the proposed equation decreased by 99.89%, 66.04%, and 61.5% as the load inclination increased from 0° to 30° for embedment ratios of 0, 1, and 2. With respect to finite element results, the average deviation of the bearing capacity obtained from the proposed equation at embedment ratios 0, 1, and 2 was 14.56%, 18.71% and 23.56%, respectively. The proposed bearing capacity equation produced results that were consistent with those reported in the literature, with an average deviation of 10.71%. [ABSTRACT FROM AUTHOR]

The high volume of vehicles at Simpang Joglo, which caused traffic congestion, became a particular focus for the government. The construction of the bridge on this railway line of PT. Wijaya Karya (WIKA) is located at KM 105+499 to KM 105 +772, with a bridge stretch of 272.80 m and a width of 14.1 m. The problems raised in this study include the effect of the implementation of bored pile work on the environment, whether the solution to the problem affects cost and time, and how much the carrying capacity of the bored pile is at this stage, using qualitative research methods and quantitative research methods. After observations and interviews with the community, it can be known that the bored pile foundation work on the Railway Elevated Line Construction Project between Solo Balapan - Kadipiro at KM 104 + 700 to KM 107 + 000 (phase 1) has several impacts that affect the work environment and the community environment, including noise, road damage, air pollution, land collapse due to drilling damage to tools, etc. From this impact, there are several solutions, including repairing road facilities, changing tools, etc. From the results of the analysis of the calculation of the bearing capacity of the foundation at Pier 11, a value of 28135.397 kN was obtained. The benefits of this research are that it can find out problems and solutions for work, know the impact on time and cost, and know the carrying capacity of a bored pile. [ABSTRACT FROM AUTHOR]

In circular shield tunnels bearing high inner pressure or rectangular shaped shield tunnels, as the axial force at the segmental lining decreases, the bolt load at the segmental joint increases. It is essential to adopt high-stiffness segmental joints to improve the bearing capacity and control the deformation at the joint position. When designing high-stiffness segmental joints, the selection of ductileiron joint panel is crucial. In this study, two types of segmental joints with different joint panels were fabricated, and the effects of joint panel stiffness on the mechanical properties of segmental joints were analyzed through full-scale sagging and hogging bending tests. The results showed that the failure mode of high-stiffness segmental joint was similar to that of large eccentric compression section. According to the difference of panel stiffness, the failure modes can be specified into two types. If the stiffness is sufficient, the joint failure occurs due to the yielding of bolts; otherwise, it occurs due to the large deformation of ductile-iron joint panels. As for the design requirement of segmental joint, the stiffness of joint panel should be sufficient, i.e., the opening and failure of the joints are finally induced by the bolt deformation. Otherwise, before the plastic deformation of the bolts, the large deformation of the joint panels will occur under a bending-moment-dominant load, and the bearing capacity of the joints will greatly decrease. [ABSTRACT FROM AUTHOR]

The suspender of a suspension bridge is susceptible to corrosion due to environment, material, load, and other factors, which leads to the reduction of its bearing capacity with time, thus adversely affecting the safety and durability of the suspension bridge. Time-variant reliability analysis can consider the time-variant characteristics and uncertainties of each variable, and can better reveal the degradation of corrosion suspender resistance with time. However, due to the complex and highly nonlinear characteristics of the stress situation, the functional function of the suspender is often implicit, and the traditional time-variant reliability analysis method cannot be directly solved. To solve the problem of the implicit function of the suspender, An Adaptive Support Vector Regression with Extreme Response Surface (ASVR-ERS) method was proposed, and it was applied to the time-variant reliability analysis of corroded suspender of a suspension bridge. According to the corrosion characteristics of steel wire in suspenders, a hybrid constitutive model for calculating the ultimate bearing capacity of corroded suspenders was proposed. Furthermore, the time-variant reliability and residual life of corroded suspenders of a self-anchored suspension bridge were systematically studied. The results show that: Compared with the existing methods, the ASVR-ERS method can use fewer training samples to achieve higher computational accuracy. When calculating the ultimate bearing capacity of a corrosion suspender, the phenomenon of ductility degradation caused by steel wire corrosion in the suspender cannot be ignored, and the mixed constitutive model of the ultimate bearing capacity of a corrosion suspender is more reasonable. When the service time of the bridge is the same, the reliability of the suspender in the middle span of the main span is the smallest, and the reliability of the suspender in the full bridge gradually decreases from the bridge tower position to the middle span direction and the side span direction. The decrease rate of suspender reliability is the fastest at the beginning of corrosion and gradually slows down with the deepening of the corrosion degree. When the sheath has the minimum damage and the maximum circumferential damage and reaches life, the suspender section loss rate is between 10 % and 15 %. Compared with improving the safety factor of the suspender, delaying the breakage time of the sheath can improve the life expectancy of the suspender more obviously. • The ASVR-ERS method has high efficiency and accuracy, and can solve the problem of implicit function of complex structure. • The hybrid constitutive model for calculating the ultimate bearing capacity of corroded suspender is more reasonable. • Compared with the design safety factor, the influence of sheath life and damage form on suspender life is more obvious. • When the suspender reaches its life due to corrosion, its cross-sectional area loss rate is between 10 % and 15 %. [ABSTRACT FROM AUTHOR]

Recently, a new steel-UHPC composite deck system is used for long-span bridges, which uses the perfobond rib (PBL) shear connectors with a thinner steel perforated plate. Because the steel perforated plate is thinner, its failure mode may be different from that of thicker steel perforated plate. To explore the shear behavior of PBL shear connectors in this new composite deck system, five sets of ten specimens are tested in this study. The parameters of the hole diameter, D , the traverse rebar diameter, d s , and the perforated steel plate thickness, t s are considered. The failure modes, strain development versus loading, and some mechanical indexes are discussed. The experiments show that the PBL shear connector with a thinner perforated steel plate causes a shear failure, while the thicker one results in bending or bending-shear failure. According to FE (finite element) analysis, the orthogonal analysis is conducted to investigate the effect of each parameter and their interaction on the mechanical behavior. It is found that the ultimate capacity and stiffness are the most sensitive to the diameter of the traverse rebar, d s , and the perforated steel plate thickness, t s. In addition, a theoretical formula is proposed to predict the bearing capacity of PBL shear connectors. The proposed formula considers the relationship between shear strain and the dilation angle for the first time. The results show a good agreement with the experiments. The study in this paper provides a good reference for the application and optimization of PBLs with a thinner steel perforated plate in new steel-UHPC composite deck system. • Introducing a new steel-UHPC bridge deck with perforated steel plate as the shear connectors and longitudinal rib. • Shear behavior on PBL shear connector in the new steel-UHPC deck is conducted. • The influence of each parameter of PBL shear connector and its interaction on the structure is obtained. • The formula for the shear capacity of PBL shear connector in the new steel-UHPC bridge deck is presented. [ABSTRACT FROM AUTHOR]

The evaluation of the bearing capacity of shallow or deep foundations is a major and traditional problem This article deals with the estimation and analysis of this bearing capacity but with a probabilistic method (statistics) therefore the main objective of this work is to do a probabilistic analysis. To answer and achieve this goal, the work has two lines of research: a theoretical one which brings together a bibliographical synthesis on the estimation of the bearing capacity of a pile by the in situ method (in place) such as the pressuremeter test and the second axis is experimental reinforced by a statistical analysis. The results of the pressuremeter test used in the evaluation (determination) of the bearing capacity of a pile considered as a deep foundation which actually represents the abutment of a rail bridge. An experimental study is underway for pressuremeter test on several sites. The geotechnical data comes according to a study of the project for the construction of a deep foundation for a bridge in the region of Tissemsilt in Algeria, after having defined the pressuremeter profile and estimated the bearing capacity by the pressuremeter method, the reliability of the results was tested. by a probabilistic (statistical) analysis using the normal distribution. [ABSTRACT FROM AUTHOR]

Stone arch bridge is an important type in the early bridge construction process because of its beautiful shape, material saving and economic rationality. However, stone material will deteriorate after long-term operation, which results in a decrease in strength and bearing capacity of stone arch bridge. The vehicle load is increasing at the same time. Therefore, accurate evaluation of bearing capacity of stone arch bridge is essential to ensure safety. In this article, a three-span open-spandrel stone arch bridge was taken as research object. Firstly, the bridge damages were investigated and analyzed in detail, and bridge service state was evaluated. Then, based on the evaluation results of disease damages and considering stone material deterioration, a refined finite element model of stone arch bridge was established to analyze bending moment, axial force, strain and deformation. Finally, static load test was carried out to test vertical deformation and stress of arch ring, horizontal displacement of pier, settlement of foundation and development of cracks. The results show that static load test is the most accurate method for evaluating bearing capacity of stone arch bridge. The evaluation accuracy of finite element model based on material correction is in the middle, and the evaluation accuracy of disease damage assessment is the worst. In practical work, bearing capacity of stone arch bridge can be evaluated by combining the three methods with high accuracy and comprehensive results. [ABSTRACT FROM AUTHOR]

The footings laid in close proximity imposes a definite change in the behaviour of the adjacent footing, subsequently changing the behaviour of the nearby footings. The present study emphasises the behaviour of the nearby strip footings embedded at a different level by adopting the commercially available finite element analysis program, ABAQUS. The load-settlement behaviour, ultimate bearing capacity (UBC), and the failure patterns of adjacent strip footings are assessed by considering the Mohr-Coulomb failure criterion. The UBC is of the nearby footings (left and right) are estimated and represented in terms of interference factors (L/R) defined as the UBC of a footing in the presence of adjacent footing to that of same considered for equivalent isolated footing. The results reveal that a significant influence of the adjacent footing is experienced when the spacing between the footings (S/B) is lesser, and they behave as the single footing of greater width at S/B = 0.25 irrespective of the level of embedment depth. Furthermore, the influence of interference increases with the increase in the embedment depth of adjacent footing. It is found that the L is significantly more for a lower level of embedment depth, and the same increases with an increase in the embedment depth of the right footing but on the contrary R decreases. The increase in the peak interference factor, L-max for DL/B = 0.5 is 2.1% and 4.2% when DR/B = 0.75 and DR/B = 1.0, respectively. [ABSTRACT FROM AUTHOR]

A lot of fieldwork is required to assess the safe bearing capacity (SBC) of fine-grained soil using IS Code, along with performing shear parameters to determine angle of internal friction and cohesion. Standard penetration tests are conducted in order to obtain N-value of soil, and evaluating atterberg limits and dry soil density. Here, it is proposed that Adaptive Neuro-Fuzzy Inference System (ANFIS) is adopted to predict fine-grained soil's safe bearing capacity. For this, input parameters considered for ANFIS system are depth of foundation, dry density, liquid limit, plasticity index, Percentage fine fraction, width/Length ratio, and N-Value. A wide range of safe bearing capacity data from various site locations was investigated and trained on. Four different models were developed with variations in membership function for each input, all the models are used with a gaussbell type of membership function. Among the four, the third model is predicting the nearest value with an R2 of 0.9738. Based on the conclusion the ANFIS model is the most reliable technique for assessing the SBC of soils. Investigation of soil properties and estimation of safe bearing capacity will be having more difficulty with respect to skilled person to investigate and time required is also more as dimension of the footing changes SBC also varies. So, to overcome this type of problems my model will give you a best suitable and reliable SBC. [ABSTRACT FROM AUTHOR]

The actual use of solid or glued timber elements that are in direct or oblique transverse bending under single or repeated loads is not considered in the current standards. In particular, the formation of folds in the compressed zone of pure bending and obtained a significant margin of safety. Therefore, the concept of "calculated cross-section" is proposed in the article. It describes the distribution of deformations in the height of the cross-section and, also, the layer-by-layer connection between deformations and stresses in a section of bending timber elements by considering the formation of folds in the compressed zone under one-time short-term or repeated loads. Therefore, the method for calculating wooden beams from solid and glued timber using a deformation model was developed. The formation of folds in the compressed zone is predicted by the method of the pure bending zone by analyzing the distribution of stresses on height in the compressed and stretched zones of the calculated cross-section. [ABSTRACT FROM AUTHOR]

The load-bearing function of articular cartilage tissue contrasts with the poor load-bearing capacity of most soft hydrogels used for its regeneration. The present study explores whether a hydrogel based on the methacrylated natural polymers chondroitin sulfate (CSMA) and hyaluronic acid (HAMA), injected into warp-knitted spacer fabrics, could be used to create a biomimetic construct with cartilage-like mechanical properties. The swelling ratio of the combined CSMA/HAMA hydrogels in the first 20 days was higher for hydrogels with a higher CSMA concentration, and these hydrogels also degraded quicker, whereas those with a 1.33 wt% of HAMA were stable for more than 120 days. When confined by a polyamide 6 (PA6) spacer fabric, the volumetric swelling of the combined CSMA/HAMA gels (10 wt%, 6.5 × CSMA:HAMA ratio) was reduced by ~53%. Both the apparent peak and the equilibrium modulus significantly increased in the PA6-restricted constructs compared to the free-swelling hydrogels after 28 days of swelling, and no significant differences in the moduli and time constant compared to native bovine cartilage were observed. Moreover, the cell viability in the CSMA/HAMA PA6 constructs was comparable to that in gelatin–methacrylamide (GelMA) PA6 constructs at one day after polymerization. These results suggest that using a HydroSpacer construct with an extracellular matrix (ECM)-like biopolymer-based hydrogel is a promising approach for mimicking the load-bearing properties of native cartilage. [ABSTRACT FROM AUTHOR]

The bearings represent an important element in the mechanical structures, ensuring the proper functioning of the moving / dynamic elements. An important feature of the bearing is its durability, which is necessary for long-term use. This characteristic is influenced by the contact between the rolling element / ring and the rolling elements / balls or rollers. This paper proposes a comparative study of the influences of different types of cylindrical roller profiles proposed in the literature and by the author on the durability characteristic. There are 3 types of profiles, standard, Fujiwara and a profile calculated by the author based on the solid of equal strength. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Southeast University (English Edition) is the property of Journal of Southeast University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The spherical bearing is widely used in highways, bridges and long-span structures. In order to study mechanical properties of a large-scale spherical bearing, a full-scale finite element model of the spherical bearing was established by using ABAQUS software, and the mechanical properties of the spherical bearing under four working conditions were simulated respectively when the upper bearing plate had different inclination angles. The ultimate bearing capacity of the spherical bearing under vertical tension was analyzed emphatically. The research results show that, in practical applications, the change in bearing capacity caused by the inclination angle of the upper bearing plate should be considered, and the wedge-shaped part should be strengthened. [ABSTRACT FROM AUTHOR]

Copyright of Gazi Üniversitesi Fen Bilimleri Dergisi Part C: Tasarım ve Teknoloji is the property of Gazi University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Understanding the load transfer mechanism and the load settlement behavior of non-connected piled raft foundations with cushion is so complicated. In the present research, based on the assumption of an axisymmetric cylindrical unit cell including pile, subsoil, cushion, and raft, an analytical model is developed and introduced. This model is capable of estimating the transferred vertical stress from raft to piles head and subsoil, compression of cushion, and differential settlement between pile head and subsoil. Also, an experimental test program has been introduced to investigate the behavior of non-connected piled raft foundations and to validate the proposed model. To represent the effectiveness of using non-connected piled raft with different cushion thickness, number, and length of piles measure with the unpiled raft, the load improvement ratio and the settlement efficiency ratio are used. According to the results, the minimum increase in the bearing capacity and the reduction in the settlement of non-connected piled raft to the unpiled raft are 42% and 38% respectively. Also, increasing the cushion thickness increases the differential settlement at the pile head elevation, and for a given number and length of pile, reduced the bearing capacity of the piled raft by 30%. The good agreement of model predictions with the experimental results is verified. The difference between the experimental and analytical values of the cushion compression above the pile head is within an acceptable range. [ABSTRACT FROM AUTHOR]

Loess soils cover approximately 10% of the Earth's land surface. Due to its honeycomb structure, this soil collapses under pressure and immediately settles when exposed to moisture. Using moisture and loading conditions prior to construction can have positive effects on the geotechnical properties of the soil and help to reduce its settlement. This study aims to investigate the effect of different installation methods of helical piles on microstructure of loess soils. A total number of 16 full-scale helical piles including single helix and double helix piles with spacing to diameter ratios of 1.5 and 3 were installed via wet and dry installation methods. These 3-m-long piles were installed at the site of Inche Borun, Golestan province, northeastern Iran. Pile static load tests were performed on a set of these piles to compare the effect of different installation methods. Furthermore, the behavior of Golestan loess was investigated by removing the soil in front of the other set of helical piles for element testing and SEM imaging. The results suggested that the combination of compressive installation load and water pressure increases the shear strength parameters of Golestan loess and accordingly, the bearing capacity of the installed helical piles. [ABSTRACT FROM AUTHOR]

Copyright of Mining of Mineral Deposits is the property of Dnipro University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Scientiarum Polonorum: Architectura is the property of Wydawnictwo SGGW and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study presented an experimental investigation on the degradation of mechanical performance of reinforced concrete (RC) columns with the reinforcements corroded under sustained loads. A total of ten RC column specimens were tested. The effects of different levels of sustained load (0%, 30%, and 60% of the designed ultimate bearing capacity Nu) and reinforcement corrosion (0%, 5%, 10%, and 20%) on the failure modes, ultimate bearing capacity, and axial load–axial deformation relationship were analyzed. The results showed that the coupling adverse effects due to the reinforcement corrosion and sustained load considerably exacerbate the mechanical deterioration of RC columns and turn the failure mode into a much more brittle manner. Compared with the control specimen L-0-0, the ultimate bearing capacity of the specimen L-4-20 could be reduced as much as about 42%. Based on the test results, an improved model was proposed to estimate the ultimate bearing capacity of corroded RC columns, in which the effects of the corrosion of both longitudinal reinforcements and stirrups and the corrosion-induced spalling of concrete cover were taken into consideration. The close agreements between the analytical predictions and test results prove the applicability of the model. [ABSTRACT FROM AUTHOR]

Piled raft foundations are sometimes used when the supporting soil has no adequate bearing capacity and the raft settlements exceed allowable values. This research investigates the bearing capacity of a foundation subjected to eccentric loads in both connected and non-connected piled raft foundations under 1 g. The load-settlement curves of a strip, square and circular raft are compared. The results illustrate that piled raft behavior is influenced by various factors such as pile length, spacing, shape, and eccentricity ratio in connected and non-connected cases. Test results indicate that connected foundations have greater bearing capacities and lesser settlements in larger pile spacing (S/D = 6), while non-connected foundations have higher bearing capacities and lesser settlements in lesser pile spacing (S/D = 3). Moreover, both the pile length in a connected piled raft system and pile spacing in a non-connected system affected the bearing capacity remarkably. The bearing capacity of the square and circular foundations at S/D = 3 was greater for the non-connected pile (19.8 and 15.8 kg/cm2 receptivity) than the connected pile (18 and 14.1 kg/cm2), while at S/D = 6, the bearing capacity of the foundations was greater for the connected pile than the non-connected pile. However, in both cases, the bearing capacity was enhanced and the settlements were reduced. The effect of various parameters is also evaluated and discussed in this study. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Southeast University (English Edition) is the property of Journal of Southeast University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Permanently shadowed regions (PSRs) are abundant at the lunar poles. They experience no direct sunlight and reach temperatures as low as 30 K. PSRs are of interest as evidence suggests that some may contain water ice (H2O/OH‐), which could provide a record of the evolution of volatiles in the inner solar system. This water ice is also a critical resource for life‐support systems and rocket propellant. A better understanding of mechanical properties of PSR regolith, such as its bearing capacity, will help optimize the design of future exploration rovers and landers. Thirteen boulder tracks were identified on the edge of, or inside, south polar lunar PSR enhanced imagery and used to estimate the strength of the PSR regolith at latitudes of 70° to 76° in sites with maximum annual temperatures of 65 to 210 K. PSR boulder track features are similar to those observed in highland, mare, and pyroclastic regions of the Moon, implying similar properties of the regolith. Measured features were used to estimate bearing capacity for PSR regolith at depths of ~0.28 to 4.68 m. Estimated bearing capacity values suggest that these PSRs may be somewhat stronger than highland and mare regions at depths of 0.28 to 1.00 m. Bearing capacity in these PSRs is statistically the same as those in other regions of the Moon at depths of 1.00 to 2.00 m. The results of this study can be used to infer bearing capacity as one measure for the trafficability of lower‐latitude PSRs of the type measured here. Plain Language Summary: The polar regions of the Moon contain areas that never experience sunlight, known as permanently shadowed regions (PSRs). These regions are thought to contain uneven distributions of water ice deposits. To access PSRs and their possible water deposits, we must first understand the strength of the soil at these locations to safely traverse them. Thirteen boulder tracks were identified on the edge of, or within, PSRs in the lunar south polar region using images taken by the Lunar Reconnaissance Orbiter. These images were processed to enable the measurement of boulders and their associated tracks. The tracks identified within PSRs have similar appearances to those identified outside PSRs in other regions on the Moon. The strength of soil within PSRs was estimated from the measurements taken and was shown to be at least as strong as highland and mare regions of the Moon at relatively shallow depths, although the studied PSRs show no evidence for the presence of water ice. Analysis shows that PSRs of the type measured here should be able to bear rovers at depths of at least ~30 cm. In situ measurements are required to confirm and better understand the mechanical behavior of PSR regolith at shallow depths. Key Points: Boulder tracks were measured from orbital imagery, and the bearing capacity of regolith in permanently shadowed regions was estimatedRegolith in permanently shadowed regions appears to be as strong as regolith found in other regions of the MoonBoulder track measurements could be used to remotely estimate the traversability of PSRs for future exploration rovers [ABSTRACT FROM AUTHOR]