摘要 :
Method of self-balanced loading test differs from the traditional methods of pile test. The key equipment of the test is a cell. The cell specially designed is used to exert load which is placed in pile body. During the test, disp...
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Method of self-balanced loading test differs from the traditional methods of pile test. The key equipment of the test is a cell. The cell specially designed is used to exert load which is placed in pile body. During the test, displacement values of the top plate and the bottom plate of the cell are recorded according to every level of load. So Q-S curves can be obtained. In terms of test results, the bearing capacity of pile can be judged. Equipments of the test are simply and cost of it is low. Under some special conditions, the method will take a great advantage. In Guangxi Province, tertiary mudstone distributes widely which is typical weak rock. It is usually chosen as the bearing stratum of pile foundation. In order to make full use of its high bearing capacity, pile is generally designed as belled pile. Foundations of two high-rise buildings which are close to each other are made up of belled socketed piles in weak rock. To obtain the bearing capacity of the belled socketed pile in weak rock, loading test in situ should be taken since it is not reasonable that experimental compression strength of the mudstone is used for design. The self-balanced loading test was applied to eight piles of two buildings. To get the best test effect, the assembly of cell should be taken different modes in terms of the depth that pile socketed in rock and the dimension of the enlarged toe. The assembly of cells had been taken three modes, and tests were carried on successfully. By the self-balanced loading test, the large bearing capacities of belled socketed piles were obtained. Several key parameters required in design were achieved from the tests. For the data of tests had been analyzed, the bearing performance of pile tip, pile side and whole pile was revealed. It is further realized that the bearing capacity of belled socketed pile in the mudstone will decrease after the mudstone it socketed in has been immerged. Among kinds of mineral ingredient in the mudstone, montmorillonite is much. And in the size composition, content of cosmid is high. For specific surface area of cosmid is large and water intake capacity of it is strong, water content has great effect on strength of the mudstone. Along with water content increasing, strength of the mudstone declines nonlinear apparently. Since effective measures had been taken, the mudstone was prohibited from being immerged during construction. And valuable experience has been accumulated for similar projects construction henceforth.
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摘要 :
Pile foundations are increasingly applied to the rapid development of long-span bridges in our country. In any kind of pile foundation a static loading test must be undertaken to determine the ultimate compressive bearing capacity...
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Pile foundations are increasingly applied to the rapid development of long-span bridges in our country. In any kind of pile foundation a static loading test must be undertaken to determine the ultimate compressive bearing capacity of a single pile under criterion GBJ7-89. The Beicha bridge test pile of the Runyang Highway Yangtze River Bridge located in the Yangtze River between Zhenjiang and Yangzhou, whose ultimate bearing capacity is up to 40,000 kN, is hardly possible to test in conventional methods. The self-balanced method (Osterberg, Load-cell) is a new static load test method, almost not limited by testing sites and ultimate bearing capacity, which can directly determine the ultimate side resistance and tip resistance. This paper discusses the method successfully applied to the test pile, instrumented with strain gauges and the method for converting the results of the self-balanced test to the conventional loading test results is put forward, which suits the design method. The results also indicate the method will have expanding prospects for testing bridge piles under conditions of high bearing capacity and for special testing sites.
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摘要 :
Pile foundations are increasingly applied to the rapid development of long-span bridges in our country. In any kind of pile foundation a static loading test must be undertaken to determine the ultimate compressive bearing capacity...
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Pile foundations are increasingly applied to the rapid development of long-span bridges in our country. In any kind of pile foundation a static loading test must be undertaken to determine the ultimate compressive bearing capacity of a single pile under criterion GBJ7-89. The Beicha bridge test pile of the Runyang Highway Yangtze River Bridge located in the Yangtze River between Zhenjiang and Yangzhou, whose ultimate bearing capacity is up to 40,000 kN, is hardly possible to test in conventional methods. The self-balanced method (Osterberg, Load-cell) is a new static load test method, almost not limited by testing sites and ultimate bearing capacity, which can directly determine the ultimate side resistance and tip resistance. This paper discusses the method successfully applied to the test pile, instrumented with strain gauges and the method for converting the results of the self-balanced test to the conventional loading test results is put forward, which suits the design method. The results also indicate the method will have expanding prospects for testing bridge piles under conditions of high bearing capacity and for special testing sites.
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This paper is intended to analyze the bearing properties and its affecting parameters of high-speed railway CFG-pile composite foundation by means of numerical simulation based on typical volume element and 3D model established wi...
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This paper is intended to analyze the bearing properties and its affecting parameters of high-speed railway CFG-pile composite foundation by means of numerical simulation based on typical volume element and 3D model established with the software FLAC 3D. The static load curves of numerical simulation accord with the field test which means the model been taken are reasonable. Take different thickness and modulus of the cushion for analysis .The results prove that the settlement of the composite foundation decreased with the increase of modulus of the cushion. And the pile-soil stress ratio increases with the increase of modulus of the cushion. With the increase of the thickness of the cushion, the settlement of the composite foundation decrease, the pile-soil stress ratio increase, and the settlement on the top of the pile decrease. When the cushion thickness is over 500mm, neither the cushion modulus nor the cushion thickness would have influence on the pile-soil stress ratio.
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摘要 :
This paper uses NI CompactRIO hardware platform, the CRIO has a small, convenient and suitable for harsh environments. Based on Labview software platform, developed vibration condition monitor data acquisition and processing syste...
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This paper uses NI CompactRIO hardware platform, the CRIO has a small, convenient and suitable for harsh environments. Based on Labview software platform, developed vibration condition monitor data acquisition and processing system, using the FPGA module and real-time processing module, realized high accuracy real-time and high sampling rate, and through wavelet analysis, processing the collected the signal. Due to the time-frequency characteristics of the wavelet analysis, the analysis of singularity of the fault signal has more advantages than the traditional spectrum analysis. Through the wavelet analysis, vibration CompactRIO system can accurate extraction of fault feature of vibration unit.
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摘要 :
This paper uses NI CompactRIO hardware platform, the CRIO has a small, convenient and suitable for harsh environments. Based on Labview software platform, developed vibration condition monitor data acquisition and processing syste...
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This paper uses NI CompactRIO hardware platform, the CRIO has a small, convenient and suitable for harsh environments. Based on Labview software platform, developed vibration condition monitor data acquisition and processing system, using the FPGA module and real-time processing module, realized high accuracy real-time and high sampling rate, and through wavelet analysis, processing the collected the signal. Due to the time-frequency characteristics of the wavelet analysis, the analysis of singularity of the fault signal has more advantages than the traditional spectrum analysis. Through the wavelet analysis, vibration CompactRIO system can accurate extraction of fault feature of vibration unit.
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The offshore wind turbine, especially the floating offshore wind turbine in the deep sea is a perspective technology in the context of increasing energy demands. Mooring system, as an important unit of the floating offshore wind t...
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The offshore wind turbine, especially the floating offshore wind turbine in the deep sea is a perspective technology in the context of increasing energy demands. Mooring system, as an important unit of the floating offshore wind turbine is emphasized. The methods of in-situ test and the laboratory experimental tests are reviewed. Some new testing methods are discussed. The most commonly used anchor systems are explored. The paper aims to present some future research work that is important for the development of the floating offshore wind turbine technology.
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摘要 :
The offshore wind turbine, especially the floating offshore wind turbine in the deep sea is a perspective technology in the context of increasing energy demands. Mooring system, as an important unit of the floating offshore wind t...
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The offshore wind turbine, especially the floating offshore wind turbine in the deep sea is a perspective technology in the context of increasing energy demands. Mooring system, as an important unit of the floating offshore wind turbine is emphasized. The methods of in-situ test and the laboratory experimental tests are reviewed. Some new testing methods are discussed. The most commonly used anchor systems are explored. The paper aims to present some future research work that is important for the development of the floating offshore wind turbine technology.
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摘要 :
In the construction process of building great bridge, steel pipe pile is often damaged by wave force. The research on the dynamic response of pile in wave-current field is attractive for practicing engineers. Base on indoor model ...
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In the construction process of building great bridge, steel pipe pile is often damaged by wave force. The research on the dynamic response of pile in wave-current field is attractive for practicing engineers. Base on indoor model test, the forces on small diameter piles in the wave-current field were studied in this paper. The model test was carried into execution aiming at the longitudinal force and the transverse force of pile under varieties of wave-current combinations. In order to compare the wave-current forces on piles, single pile and double piles which were designed to tandem and juxtaposition were researched respectively. The longitudinal force and the transverse force of the single pile and the pile group under varieties of wave-current combinations were obtained by the two-component balance. Finally, the variation of the drag force coefficient CD and inertia force coefficient CM in Morison equation with the KC number is studied. The influences of the layout of the piles to the wave forces acting on the specific pile, as well as to the flow field are discussed. The research results indicate that there is a close relationship between the forces of the pile in pile group and the spacing diameter ratio. In addition, the test results reveal that the transverse force has more randomness, and its peak value can be approach the longitudinal force. The result of research can provide references for practical project and further study.
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摘要 :
In the construction process of building great bridge, steel pipe pile is often damaged by wave force. The research on the dynamic response of pile in wave-current field is attractive for practicing engineers. Base on indoor model ...
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In the construction process of building great bridge, steel pipe pile is often damaged by wave force. The research on the dynamic response of pile in wave-current field is attractive for practicing engineers. Base on indoor model test, the forces on small diameter piles in the wave-current field were studied in this paper. The model test was carried into execution aiming at the longitudinal force and the transverse force of pile under varieties of wave-current combinations. In order to compare the wave-current forces on piles, single pile and double piles which were designed to tandem and juxtaposition were researched respectively. The longitudinal force and the transverse force of the single pile and the pile group under varieties of wave-current combinations were obtained by the two-component balance. Finally, the variation of the drag force coefficient CD and inertia force coefficient CM in Morison equation with the KC number is studied. The influences of the layout of the piles to the wave forces acting on the specific pile, as well as to the flow field are discussed. The research results indicate that there is a close relationship between the forces of the pile in pile group and the spacing diameter ratio. In addition, the test results reveal that the transverse force has more randomness, and its peak value can be approach the longitudinal force. The result of research can provide references for practical project and further study.
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