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A new type of static load test system and test method based on steel screw anchor pile is proposed. Through field uplift tests of single pile and pile group, the influence of soil properties, pile length and other factors on the uplift bearing capacity of steel screw pile is analyzed. The influence range of steel screw pile on the displacement of adjacent soil and pile foundation are revealed. The calculation method of ultimate uplift bearing capacity of single steel screw anchor pile is established. The reliability of the test method is verified by practical cases. The test results show that the uplift bearing capacity of steel screw pile is higher than that of straight rod pile. According to the properties and compactness of the soil, the coefficient of uplift side resistance improvement of steel screw piles can be taken as 1.2 – 1.6. The construction of steel screw pile is convenient and can be reused, without special treatment of the test site. The test method can save up to 70% of the cost compared with traditional surcharge test method, and greatly improve the safety of large-tonnage static load test. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Railway Science & Engineering is the property of Journal of Railway Science & Engineering 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 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]

The high-strain direct testing method is a novel technique for dynamic testing of pile bearing capacity, developed as an improvement to the traditional high-strain method. While its theoretical feasibility has been demonstrated through numerical simulations and laboratory experiments, its effectiveness in practical engineering applications remains uncertain. This paper discusses the foundational theory of the high-strain direct testing method, highlighting its clear calculation principles, straightforward process, and advantage of not requiring iterative fitting. The bridge project in Zhuhai, Guangdong Province, China, serves as a case study. An instrumentation layout for concrete-filled piles was designed based on the principles of the high-strain direct testing method, and data processing and analysis programs were developed using Python. Fifteen test piles were selected for field application of the high-strain direct testing method, with detailed analysis conducted on the results from four test piles. The test results were consistent with the soil layer distribution characteristics beneath the four piers of the bridge, validating the feasibility of this method in actual engineering practice. Subsequent static load tests on these four test piles allowed for a comparison with the high-strain direct testing method results, confirming the accuracy and reliability of the high-strain direct testing method for determining the bearing capacity of single piles. Furthermore, this paper identifies sources of error in the application of this method and proposes corresponding improvement measures. As this method directly derives results from instrumented measurements, it is theoretically applicable to piles of any cross-sectional shape and material, provided that enough measurement lines can be successfully arranged along the pile shaft. This capability allows for the real-time estimation of the ultimate bearing capacity during pile driving, thereby enhancing the universality of the high-strain direct dynamic testing method beyond traditional techniques. [ABSTRACT FROM AUTHOR]

This paper presents an analysis of long, large-diameter bored piles' behavior under static and dynamic load tests for a megaproject located in El Alamein, on the northern shoreline of Egypt. Site investigations depict an abundance of limestone fragments and weak argillaceous limestone interlaid with gravelly, silty sands and silty, gravelly clay layers. These layers are classified as intermediate geomaterials, IGMs, and soil layers. The project consists of high-rise buildings founded on long bored piles of 1200 mm and 800 mm in diameter. Forty-four (44) static and dynamic compression load tests were performed in this study. During the pile testing, it was recognized that the pile load–settlement behavior is very conservative. Settlement did not exceed 1.6% of the pile diameter at twice the design load. This indicates that the available design manual does not provide reasonable parameters for IGM layers. The study was performed to investigate the efficiency of different approaches for determining the design load of bored piles in IGMs. These approaches are statistical, predictions from static pile load tests, numerical, and dynamic wave analysis via a case pile wave analysis program, CAPWAP, a method that calculates friction stresses along the pile shaft. The predicted ultimate capacities range from 5.5 to 10.0 times the pile design capacity. Settlement analysis indicates that the large-diameter pile behaves as a friction pile. The dynamic pile load test results were calibrated relative to the static pile load test. The dynamic load test could be used to validate the pile capacity. Settlement from the dynamic load test has been shown to be about 25% higher than that from the static load test. This can be attributed to the possible development of high pore water pressure in cohesive IGMs. The case study analysis and the parametric study indicate that AASHTO LRFD is conservative in estimating skin friction, tip, and load test resistance factors in IGMs. A new load–settlement response equation for 600 mm to 2000 mm diameter piles and new recommendations for resistance factors φ qp, φ qs, and φ load were proposed to be 0.65, 0.70, and 0.80, respectively. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Architecture & Civil Engineering is the property of Chang'an Daxue Zazhishe 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.)

We tested the hypothesis that the loss of load-bearing capacity, as estimated by means of static load tests and from sonic tomography, is comparable. This is of practical importance for arborists when they have to assess results reported by different consultants or when they have to choose between applying one of these two methods in a specific case. A total of 59 trees, primarily Fagus sylvatica and Quercus robur, were subjected to static load tests and sonic tomography. The pulling test method yielded the residual stiffness of the stem at every position tested with a strain sensor as an intermediate quality parameter used to merely validate the actual estimations of safety against fracture. Based on the shape of the parts of the stem cross-section that are considered load bearing, sonic tomograms can be further processed in order to assess the loss of load-bearing capacity from defects like decay. We analyzed the correlation of these biomechanically equivalent parameters. This was only the case to a very limited extent. Sonic tomography and static load tests cannot replace each other, but they can complement each other. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of the L.N. Gumilyov Eurasian National University. Technical science & Technology series is the property of L.N. Gumilyov Eurasian National 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.)

The paper presents the results of the study of the proposed type of variable profile piles. The proposed type of piles is reinforced concrete driven piles segmented in length. Each subsequent section has a radial displacement along the axis of symmetry relative to the previous section. The positive effect of the performance of the proposed pile is to change the nature of the lateral contact of the pile with the soil, and to increase the drag of the soil. The conducted research is aimed at solving the problem related to the relatively low bearing capacity of traditional square section piles. The research was carried out by the method of model tests of piles on a test bench (tray) at a scale of 1:10. The tests were performed for variant pile types in comparison with a standard square section prismatic pile. The adopted dimensions of the pile model allow the use of this tray without the influence of its boundary conditions on the stress-strain state of the soil. A total of 42 tests were performed, 3 tests for each type of piles compared. Evaluation of pile bearing capacity was performed by static loading of pile models with vertical indentation load until failure. According to the results of the investigations, the resistance values of the compared pile types in the soil were obtained, as well as the dependence of bearing capacity changes on the section dimensions and on the rotation angle. According to the results, the optimal pile solution was selected. The bearing capacity of the proposed optimal pile solution exceeds the bearing capacity of the standard driven pile by 22 %. The results obtained allow us to conclude about the influence of the technological solution of the proposed pile type on its serviceability in soil conditions [ABSTRACT FROM AUTHOR]

Modern road construction uses a large number of polymer-based materials. Material composition depends on their roles. Among the most important functions of road body materials is to transfer all loads safely to the subgrade. A thorough understanding of material properties in various climates is crucial for this purpose. In the automotive industry, polymer residues from recycling can be used to make innovative materials, such as STERED, a hybrid polymer composite. Drawing on the porous nature of this material, this paper investigates its mechanical behavior. For road construction, the compressive properties of the material are most important. The paper presents the results of a detailed analysis and experimental research of the STERED material from in-lab tests. Successful research will lead to the inclusion of the material in road body compositions with excellent retention properties, vibration damping, and potential in circular economy. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Ground Improvement is the property of Journal of Ground Improvement 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.)

This paper describes a method for continuously measuring the contact position between the wheel and rail using strain gauges. The authors investigated the relationship between the bridge output sensitivity rate and the change in the placement of strain gauges using the result of finite element analysis for the instrumented wheelset. It is noted that the bridge output sensitivity rate is defined as the bridge output change per unit distance of the contact position (load position). Based on the result, strain gauges position suitable for measuring contact position was identified. On the other hand, static load tests were conducted on the instrumented wheelset with strain gauges attached to measure contact forces (wheel load, lateral force, and tangential force) and positions, respectively. The test results were found to be generally consistent with the finite element analysis results, and it was also observed that the load position of each contact force influenced each bridge output. Finally, this paper proposes a method for calculating the contact position by solving a nonlinear equation. The calculation uses the results of the load tests and also wheel rotation angle, bridge outputs, wheel load, lateral force and tangential force which measured in running railway vehicle. Simulations were performed for various cases, and the contact positions were obtained stably and continuously. This suggests that the proposed method is reasonable and applicable to various situations.

Copyright of Railway Construction Technology is the property of Railway Construction 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.)

The large-span prestressed concrete beam bridge has been widely used due to its advantages of high structural stiffness, smooth and comfortable traffic, good seismic performance, and mature construction technology. However, after a long period of service, such bridges may develop cracks in their structure due to the long-term effects of natural environment and overloading, which can affect their safe carrying capacity. This problem is particularly prominent for long-span bridges over the sea. Therefore, in order to accurately assess the actual working condition and carrying capacity of an in- service long-span prestressed concrete beam bridge over the sea, on-site static and dynamic load tests on a bridge that has been in service for 15 years are conducted. The characteristics such as vibration mode were analyzed using finite element analysis. The research results indicate that the structural performance of the bridge remains good, but the actual carrying capacity has decreased due to structural damage and crack formation caused by the environmental conditions in the marine area and long-term service. The findings of this study can provide reference for the maintenance and strengthening of similar in-service bridges. [ABSTRACT FROM AUTHOR]

In order to study the mechanical properties of mechanically connected nodes of double-web I-beam GFRP girders, based on static load tests of two types of glass fiber reinforced polymer(GFRP) girders without and with mechanical connections, the force characteristics of double-web I-beam GFRP girders under symmetric loading at three points were analyzed, and the limit states and damage forms of the two types of girders were clarified. The results show that the GFRP waist beam adopts double web I-beam crosssection type, and the maximum stress of the cross-section is 183 MPa, which is 62% of the longitudinal tensile strength and 73% of the longitudinal compressive strength of the GFRP waist beam (205% of the allowable compressive load capacity), which can make the GFRP material strength fully developed and the waist beam has good stability performance. GFRP waist beam is prone to local damage, firstly, local instability occurs at the flange plate, which then causes buckling damage to the web, surface peeling and bulging at the connection of flange and web, and the additional splice plate and bolts at the connection of waist beam can effectively suppress the local damage deformation. Adopting bolt mechanical connection and adding the same material splice plate at the connection can reduce the weakening effect of bolt drilling on the cross-section of the beam itself, so that the stiffness and ultimate bearing capacity of GFRP waist beam can be increased by 17. 9% and 44. 9% respectively, which is a reasonable connection method for GFRP waist beam. The research results can provide reference and reference for the promotion and application of GFRP girders. [ABSTRACT FROM AUTHOR]

Copyright of New Building Materials / Xinxing Jianzhu Cailiao is the property of New Building Materials 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.)

In order to study the vertical bearing characteristics of dynamically driven piles on mudstone foundation, the vertical compressive static load test of single piles driven on mudstone foundation was carried out to analyze the sink penetration and bearing characteristics of the test piles, and to discuss the influence of groundwater on the bearing performance of the test piles, and to evaluate the applicability of the model by comparing and analyzing the calculated values of the ultimate bearing capacity of single piles from different theoretical prediction models based on the results of the static load test. Research shows that the ultimate bearing capacity of the test pile is related to the piling energy, and different piling energies cause different degrees of disturbance damage to the mudstone around the pile, which in turn affects the bearing performance of the test pile. Comparing the damage of the test pile with the mudstone around the pile in water, it is found that there is no direct relationship between the softening of the mudstone around the pile in water and the damage of the pile. Comparing the predicted ultimate bearing capacity results of different models, it is considered that the hyperbolic model is more suitable for the nature of the mudstone at this test site, and the predicted curve variation trend and the measured value are in good agreement. The reason for the large difference between the predicted value of the exponential model and the measured value is the abnormal damage of the test pile at the last level of loading. The pile driven into the mudstone foundation is affected by the super pore water pressure, soft and hard interlayer and the disturbance of the piling process, and the single pile bearing capacity has instability to a large extent. [ABSTRACT FROM AUTHOR]

Cast-in-place pile is widely used in urban construction because of its advantages of high bearing capacity, mature construction technology and high degree of construction mechanization. To determine the bearing characteristics of cast-in-place piles effectively and to master the testing methods of bearing characteristics are the prerequisite and guarantee for the safe use of structures. For this reason, focusing on the bearing characteristics of cast-in piles and the key testing methods of bearing characteristics, the latest research status at home and abroad was summarized and reviewed. The influencing factors and load transfer rules of cast-in-place pile bearing characteristics were systematically summarized. The principle and characteristics of testing methods for integrity and bearing characteristics of cast-pile such as low strain method, acoustic transmission method, high strain method, static load test and self-balancing test were introduced. The latest research progress of distributed optical fiber testing technology in load bearing performance testing of cast-in-place piles was briefly introduced. Based on the existing research results, the end resistance, side friction resistance and load transfer rule of pile were summarized and analyzed. Finally, based on the current research on the bearing characteristics of cast-inplace piles and testing methods, there were deficiencies and defects. Some suggestions and measures were put forward to promote the progress and development of testing methods for bearing characteristics of cast-in-situ piles. [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.)

A bored pile provides a large capacity obtained to toe and friction pile to support some loads such as axial, lateral, and tensile due to hydrostatic pressure or overturning moment. Static and dynamic load tests are often carried out to validate pile design before pile production in a project. This study aims to compare the ultimate capacity of the pile based on the result of static load test, dynamic load test, and pile design in granular soil of Batam, Indonesia, in which Chin-Kondner, Mazurkiewicz, Davisson, and Hansen 80% methods are utilized to obtain ultimate capacity (Qu) of static load test and dynamic test analysis apply Case Pile Wave Analysis Program (CAPWAP) method to gain ultimate capacity. The result analysis of the static load test of ultimate capacity using Chin-Kondner, Mazurkiewicz, Davisson, and Hansen 80% methods obtained results of 1379, 1300, 1375, and 1182 tons, respectively, with a Qu average of 1309 tons. A bearing capacity (RMX) of 1204 tons was obtained through a dynamic load test. Using the CAPWAP method based on the dynamic test, the ultimate bearing capacity (Ru) of 1248 tons was obtained. Analysis of pile design shows that the ultimate capacity of the bored pile in the granular soil of Batam, Indonesia, was 1157 tons. The Qu examination between field loading testing (1278.5 tons) and design pile foundation (1158 tons) was 9.4%.

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.

The high-strain direct testing method is a novel technique for dynamic testing of pile bearing capacity, developed as an improvement to the traditional high-strain method. While its theoretical feasibility has been demonstrated through numerical simulations and laboratory experiments, its effectiveness in practical engineering applications remains uncertain. This paper discusses the foundational theory of the high-strain direct testing method, highlighting its clear calculation principles, straightforward process, and advantage of not requiring iterative fitting. The bridge project in Zhuhai, Guangdong Province, China, serves as a case study. An instrumentation layout for concrete-filled piles was designed based on the principles of the high-strain direct testing method, and data processing and analysis programs were developed using Python. Fifteen test piles were selected for field application of the high-strain direct testing method, with detailed analysis conducted on the results from four test piles. The test results were consistent with the soil layer distribution characteristics beneath the four piers of the bridge, validating the feasibility of this method in actual engineering practice. Subsequent static load tests on these four test piles allowed for a comparison with the high-strain direct testing method results, confirming the accuracy and reliability of the high-strain direct testing method for determining the bearing capacity of single piles. Furthermore, this paper identifies sources of error in the application of this method and proposes corresponding improvement measures. As this method directly derives results from instrumented measurements, it is theoretically applicable to piles of any cross-sectional shape and material, provided that enough measurement lines can be successfully arranged along the pile shaft. This capability allows for the real-time estimation of the ultimate bearing capacity during pile driving, thereby enhancing the universality of the high-strain direct dynamic testing method beyond traditional techniques.

This paper presents an analysis of long, large-diameter bored piles’ behavior under static and dynamic load tests for a megaproject located in El Alamein, on the northern shoreline of Egypt. Site investigations depict an abundance of limestone fragments and weak argillaceous limestone interlaid with gravelly, silty sands and silty, gravelly clay layers. These layers are classified as intermediate geomaterials, IGMs, and soil layers. The project consists of high-rise buildings founded on long bored piles of 1200 mm and 800 mm in diameter. Forty-four (44) static and dynamic compression load tests were performed in this study. During the pile testing, it was recognized that the pile load–settlement behavior is very conservative. Settlement did not exceed 1.6% of the pile diameter at twice the design load. This indicates that the available design manual does not provide reasonable parameters for IGM layers. The study was performed to investigate the efficiency of different approaches for determining the design load of bored piles in IGMs. These approaches are statistical, predictions from static pile load tests, numerical, and dynamic wave analysis via a case pile wave analysis program, CAPWAP, a method that calculates friction stresses along the pile shaft. The predicted ultimate capacities range from 5.5 to 10.0 times the pile design capacity. Settlement analysis indicates that the large-diameter pile behaves as a friction pile. The dynamic pile load test results were calibrated relative to the static pile load test. The dynamic load test could be used to validate the pile capacity. Settlement from the dynamic load test has been shown to be about 25% higher than that from the static load test. This can be attributed to the possible development of high pore water pressure in cohesive IGMs. The case study analysis and the parametric study indicate that AASHTO LRFD is conservative in estimating skin friction, tip, and load test resistance factors in IGMs. A new load–settlement response equation for 600 mm to 2000 mm diameter piles and new recommendations for resistance factors φqp, φqs, and φload were proposed to be 0.65, 0.70, and 0.80, respectively.

The bearing capacity of screw cast in situ displacement piles is mostly unexplored. There is also insufficient research on piles in silty soils. Therefore, five cone penetration tests (CPT) and one piezocone penetration test (CPTu) using direct methods were utilised to determine the load-bearing capacity of four displacement piles in Estonia. In addition to the CPT sounding data, static-dynamic test (SDT) results were used to analyse the load-beating capacity of the piles. Both deterministic and probabilistic methods were used in the analysis. Characteristic values as a 95% reliable mean and 5% fractile values for sounding parameters, according to the Eurocode 7, were included. Additionally, Monte Carlo simulation was included in the reliability-based design (RBD). The bearing capacities of screw cast in situ displacement piles in silty soils, here based on the CPT and SDT sounding data, were similar. The adaptation of SDT results for the CPT direct methods for pile load-bearing capacity analysis certainly deserves attention and further investigation. For both sounding types, the Eurocode 7 method provided the best results for all piles. The results of pile-bearing capacities in the absolute difference varied within ±11% between the average, RBD and characteristic values.

In concealed underground projects, pile foundations may cause severe engineering accidents owing to factors such as construction technology, geological conditions, and material properties. Accordingly, the construction industry has invariably focused on developing high-precision, distributed, and low-cost monitoring and disaster warning methods. Therefore, a new sensing material, sensor-enabled piezoelectric geocable (SPGC), was developed to monitor the deformation and failure of a pile foundation. Three model piles were constructed, and packaging and layout processes for the SPGC sensing material were proposed. Moreover, a fiber Bragg grating (FBG) sensor and resistance strain gauge were installed for comparison. Pile foundation failure and static load tests were performed using a large servo hydraulic press. The monitored effect was evaluated by obtaining the impedance and voltage signals of the SPGC. Pile foundation failure test results show that the mutation of impedance and voltage signals can be used as combined monitoring data, and the electrical signal of the SPGC can be used in three stages of early warning response. These findings ensure that pile foundation damage can be located, damage precursors can be identified, and timely warning can be provided. The static load test results indicate that the SPGC data are in good agreement with the FBG sensor and strain gauge data. The impedance of the SPGC increases linearly with the load. Accordingly, a linear calculation formula relating impedance and strain is derived. The research results are expected to provide a new technical method for pile foundation construction and long-term operation and maintenance monitoring. [ABSTRACT FROM AUTHOR]

Copyright of Guangdong Architecture Civil Engineering is the property of Guangdong Architecture Civil Engineering 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.)

Copyright of Guangdong Architecture Civil Engineering is the property of Guangdong Architecture Civil Engineering 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.)

Pipe piles have been widely used in composite foundation treatment by virtue of the advantages of assembly line production, easy control of pile quality, fast construction, high bearing capacity of single pile and green environmental protection. By introducing elastic cushion in the static load test method of pipe pile composite foundation, and using theoretical analysis and field test to study the change rule of settlement, pile-soil stress ratio and pile top stress of pipe pile composite foundation with different cushion stiffness. It is concluded that it is feasible to replace the sand cushion layer recommended by the current specification with elastic cushion layer. The study shows that the elastic cushion method of static load test of pipe pile composite foundation is closer to the bearing state of real working condition. The elastic cushion has better pile-soil stress adjustment effect, which is more responsive to the stress adjustment effect of actual engineering cushion, and the elastic cushion provides an improved method for the static load test method of composite foundation. [ABSTRACT FROM AUTHOR]

Copyright of Railway Construction Technology is the property of Railway Construction 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.)

Copyright of Journal of Architecture & Civil Engineering is the property of Chang'an Daxue Zazhishe 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 Journal of Railway Science & Engineering is the property of Journal of Railway Science & Engineering 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.)

Copyright of Guangdong Architecture Civil Engineering is the property of Guangdong Architecture Civil Engineering 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.)

Copyright of Railway Construction Technology is the property of Railway Construction 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.)

As a new type of grain barn wall component, the "Structure-Insulation" integrated wall panel (SIW) has excellent characteristics such as a high-bearing capacity and good insulation performance. In order to study its mechanical properties under grain load, this paper designed three wall panels with different thicknesses, carried out static loading tests on them, studied their cracking and ultimate load, and analyzed the development trend of the wall panel's crack and deflection. In order to study the reliability of wall panels under stochastic conditions, the performance functions of the wall panel under deflection and strength control conditions were established. The reliability analysis was carried out by using the response surface method and finite element software. The sensitivity degree of each random parameter to different performance functions was quantified. The results show that, under the maximum grain load condition, the deflection of the designed specimens is less than l0/250, and the crack width is less than 0.2 mm, both of which meet the requirements of the normal use limit state. The cracking loads of the three specimens are 13.02, 14.75, and 16.49 kN/m2, respectively, with corresponding crack widths of 0.06, 0.07, and 0.06 mm. The ultimate load is 65.1, 75.52, and 82.47 kN/m2, with corresponding maximum crack widths of 1.66, 1.60, and 1.61 mm, respectively. The reliability indexes of the deflection and strength of the thinnest specimens are β 1 = 2.60 and β 2 = 3.26 , respectively, which meet the safety conditions of ductile failure. The parameter affecting the reliability of concrete deflection is the grain gravity density, with a correlation coefficient of −0.707. The parameter affecting the reliability of concrete strength is concrete strength, with a correlation coefficient of 0.935. Combined with the static load test and reliability analysis, the designed wall panel can meet the normal use of grain under full load and has good reliability. Sensitivity analysis can provide a reference for the optimization of practical engineering design. [ABSTRACT FROM AUTHOR]

Plugging of open-ended pipe piles affects the drivability and the capacity of the pile. Depending on their geometrical and geotechnical properties, as well as the driving dynamics, piles can be Plugged, Unplugged, or Partially Plugged. However, forecasting the plugging condition confidently, ahead of driving, has not been yet established, often resulting in driving difficulties. In this study, ten Machine Learning (ML) algorithms, namely: (i) Support Vector Machine (SVM); (ii) Logistic Regression; (iii) k-Nearest Neighbor; (iv) Decision Tree; (v) Random Forest; (vi) AdaBoost; (vii) XGBoost; (viii) Multi-Layer Perceptron (MLP); (ix) Hard Voting Classifier; and (x) Soft Voting Classifier, were explored in an effort to forecast the plugging condition using a dataset of 144 open-ended pipe piles. The calculated capacities were determined using four methods. These capacities were compared to measured (interpreted) capacities from static load tests for the purpose of identification of plugging in load tests where the information was not recorded. Sixteen different combinations that encompass geometric properties (diameter (D), length (L), L/D ratio, thickness) and geotechnical properties (predominant soil type, soil at pile toe, number of soil layers in the profile) for the piles were used as inputs for the ten ML algorithms. The highest achieved accuracy in identifying presumed plugging was 74% using a Soft Voting Classifier with the diameter, L/D ratio, and thickness as inputs. The model was finally tested using 24 published load tests and achieved similar accuracy. [ABSTRACT FROM AUTHOR]

Many bridges suffer from aging and deterioration problems and need to be strengthened. PSWR-PUC is an emerging structural strengthening technology that enhances the load-bearing capacity of concrete bridges by embedding prestressed steel wire ropes into polyurethane cement. This paper focuses on investigating the shear reinforcement effectiveness of PSWR-PUC. Firstly, the composition of PSWR-PUC is introduced. Subsequently, two T-beam bridges in similar service condition are selected, and shear strengthening schemes involving PSWR-PUC and externally bonded steel plates are devised. Lastly, static loading tests are conducted, and the deflection and strain data of the two bridges before and after reinforcement intervention are analyzed. The results indicate that both strengthening methods improve the bridge load-carrying capacity. However, compared to the bridge strengthened with the externally bonded steel plate method, the deflections in the bridge strengthened with PSWR-PUC decreased by 36.8% and 42.1%, the strains decreased by 18% and 23%, and the shear stiffness was improved to a greater extent. These results verified that the PSWR-PUC strengthening method is effective for improving structural capacity and performance. This study will contribute to an in-depth understanding of the performance characteristics and application scope of PSWR-PUC shear strengthening technology, and it provides a scientific basis and guidance for practical engineering applications. [ABSTRACT FROM AUTHOR]

Bridge deformation monitoring usually adopts contact sensors, and the implementation process is often limited by the environment and observation conditions, resulting in unsatisfactory monitoring accuracy and effect. Ground-Based Synthetic Aperture Radar (GBSAR) combined with corner reflectors was used to perform static load-loaded deformation destruction experiments on solid model bridges in a non-contact manner. The semi parametric spline filtering and its optimization method were used to obtain the monitoring results of the GBSAR radar’s line of sight deformation, and the relative position of the corner reflector and the millimeter level deformation signals under different loading conditions were successfully extracted. The deformation transformation model from the radar line of sight direction to the vertical vibration direction was deduced. The transformation results of deformation monitoring and the measurement data such as the dial indicator were compared and analyzed. The occurrence and development process of bridge deformation and failure were successfully monitored, and the deformation characteristics of the bridge from continuous loading to eccentric loading until bridge failure were obtained. The experimental results show that GBSAR combined with corner reflector can be used for deformation feature acquisition, damage identification and health monitoring of bridges and other structures, and can provide a useful reference for design, construction and safety evaluation.

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.