The bearing capacity testing and evaluation of the existing bridge engineering structure is not only the key to clarify its structural quality and safety performance,but it also can lay a solid foundation for subseque...The bearing capacity testing and evaluation of the existing bridge engineering structure is not only the key to clarify its structural quality and safety performance,but it also can lay a solid foundation for subsequent repairs and maintenance work.To ensure the bearing capacity,durability and reliability of existing bridges,this paper analyzes the importance and methods of testing and evaluation of structural bearing capacity of a bridge.This analysis aims to provide scientific reference for the quality assessment and subsequent repair and maintenance of existing bridge engineering structures.展开更多
A new method of detecting the vertical bearing capacity for single-pile with high strain is discussed in this paper. A heavy hammer or a small type of rocket is used to strike the pile top and the detectors are used ...A new method of detecting the vertical bearing capacity for single-pile with high strain is discussed in this paper. A heavy hammer or a small type of rocket is used to strike the pile top and the detectors are used to record vibra- tion graphs. An expression of higher degree of strain (deformation force) is introduced. It is testified theoretically that the displacement, velocity and acceleration cannot be obtained by simple integral acceleration and differential velocity when long displacement and high strain exist, namely when the pile phase generates a whole slip relative to the soil body. That is to say that there are non-linear relations between them. It is educed accordingly that the force P and displacement S are calculated from the amplitude of wave train and (dynamic) P-S curve is drew so as to determine the yield points. Further, a method of determining the vertical bearing capacity for single-pile is dis- cussed. A static load test is utilized to check the result of dynamic test and determine the correlative constants of dynamic-static P(Q)-S curve.展开更多
In this work, a new porous Zrobased metal-organic framework （MOF） with a large Brunner-Emmet-Teller （BET） surface area was prepared by the solvothermal method using 4,4＇-（naphthalene-1,4-diyl）dibenzoic acid （N...In this work, a new porous Zrobased metal-organic framework （MOF） with a large Brunner-Emmet-Teller （BET） surface area was prepared by the solvothermal method using 4,4＇-（naphthalene-1,4-diyl）dibenzoic acid （NDDA） as the organic ligand, and the luminescent detection performance was studied systematically. The experiments comb- ing with computations indicate that the as-synthesized material can sensitively and selectively detect nitro explo- sives and metal ions, especially for 2,4,6-trinitrophenol （TNP） and Fe3＋, due to the possible electron transfer from inorganic moieties to organic moieties with naphthalene part. Interestingly, owing to its high porosity and large sur- face area, this Zr-MOF showed quick luminescent response time （in 1 min） for TNP and Fe3＋. The results obtained may provide useful information for the design of MOFs with the large permanent porosity in sensing applications for large molecules in the future.展开更多
文摘The bearing capacity testing and evaluation of the existing bridge engineering structure is not only the key to clarify its structural quality and safety performance,but it also can lay a solid foundation for subsequent repairs and maintenance work.To ensure the bearing capacity,durability and reliability of existing bridges,this paper analyzes the importance and methods of testing and evaluation of structural bearing capacity of a bridge.This analysis aims to provide scientific reference for the quality assessment and subsequent repair and maintenance of existing bridge engineering structures.
文摘A new method of detecting the vertical bearing capacity for single-pile with high strain is discussed in this paper. A heavy hammer or a small type of rocket is used to strike the pile top and the detectors are used to record vibra- tion graphs. An expression of higher degree of strain (deformation force) is introduced. It is testified theoretically that the displacement, velocity and acceleration cannot be obtained by simple integral acceleration and differential velocity when long displacement and high strain exist, namely when the pile phase generates a whole slip relative to the soil body. That is to say that there are non-linear relations between them. It is educed accordingly that the force P and displacement S are calculated from the amplitude of wave train and (dynamic) P-S curve is drew so as to determine the yield points. Further, a method of determining the vertical bearing capacity for single-pile is dis- cussed. A static load test is utilized to check the result of dynamic test and determine the correlative constants of dynamic-static P(Q)-S curve.
基金Financial support by the National Key Basic Re- search Programof China （＂973＂） （No. 2013CB733503）, the National Natural Science Foundation of China （Nos. 21606007, 21136001 and 21536001） and the Funda- mental Research Funds for the Central Universities （No. ZY1509） is greatly appreciated.
文摘In this work, a new porous Zrobased metal-organic framework （MOF） with a large Brunner-Emmet-Teller （BET） surface area was prepared by the solvothermal method using 4,4＇-（naphthalene-1,4-diyl）dibenzoic acid （NDDA） as the organic ligand, and the luminescent detection performance was studied systematically. The experiments comb- ing with computations indicate that the as-synthesized material can sensitively and selectively detect nitro explo- sives and metal ions, especially for 2,4,6-trinitrophenol （TNP） and Fe3＋, due to the possible electron transfer from inorganic moieties to organic moieties with naphthalene part. Interestingly, owing to its high porosity and large sur- face area, this Zr-MOF showed quick luminescent response time （in 1 min） for TNP and Fe3＋. The results obtained may provide useful information for the design of MOFs with the large permanent porosity in sensing applications for large molecules in the future.
