The mode of load and deformation of directional drilling string and the expression of trigonometric series of deflection equation are established by means of elastic deformation energy and of the vertical and horizont...The mode of load and deformation of directional drilling string and the expression of trigonometric series of deflection equation are established by means of elastic deformation energy and of the vertical and horizontal bending. A calculation formula for natural frequency of horizontal resonance and rotational speed is derived based on the calculation method by Ritz, with which analysis is made for the cause and affecting factors of the excessive abrasion of heavy-weight drill pipe in high-angle holes so as to provide reference and basis for rational selection of drilling parameters and drilling tools in the future high-angle directional drilling.展开更多
Bi-directional static loading test adopting load cells is widely used around the world at present, with increase in diameter and length of deep foundations. In this paper, a new simple conversion method to predict the...Bi-directional static loading test adopting load cells is widely used around the world at present, with increase in diameter and length of deep foundations. In this paper, a new simple conversion method to predict the equivalent pile head load-settlement curve considering elastic shortening of deep foundation was put forward according to the load transfer mechanism. The proposed conversion method was applied to root caisson foundation in a bridge and to large diameter pipe piles in a sea wind power plant. Some new load cells, test procedure, and construction technology were adopted based on the applications to different deep foundations, which could enlarge the application scopes of bi-directional loading test. A new type of bi-directional loading test for pipe pile was conducted, in which the load cell was installed and loaded after the pipe pile with special connector has been set up. Unlike the conventional bi-directional loading test, the load cell can be reused and shows an evident economic benefit.展开更多
The vibration and control of pipes conveying fluid is studied. The solid-liquid coupling vibration equations of the pipe conveying fluid are deduced by Hamilton principle.The direct velocity feedback is used to contro...The vibration and control of pipes conveying fluid is studied. The solid-liquid coupling vibration equations of the pipe conveying fluid are deduced by Hamilton principle.The direct velocity feedback is used to control the pipe vibration. The whip response and control are discussed.展开更多
文摘The mode of load and deformation of directional drilling string and the expression of trigonometric series of deflection equation are established by means of elastic deformation energy and of the vertical and horizontal bending. A calculation formula for natural frequency of horizontal resonance and rotational speed is derived based on the calculation method by Ritz, with which analysis is made for the cause and affecting factors of the excessive abrasion of heavy-weight drill pipe in high-angle holes so as to provide reference and basis for rational selection of drilling parameters and drilling tools in the future high-angle directional drilling.
基金Supported by the National Natural Science Foundation of China (50908048)the Priority Academic Program Development (PAPD) Project of JiangsuHigher Education Institutions
文摘Bi-directional static loading test adopting load cells is widely used around the world at present, with increase in diameter and length of deep foundations. In this paper, a new simple conversion method to predict the equivalent pile head load-settlement curve considering elastic shortening of deep foundation was put forward according to the load transfer mechanism. The proposed conversion method was applied to root caisson foundation in a bridge and to large diameter pipe piles in a sea wind power plant. Some new load cells, test procedure, and construction technology were adopted based on the applications to different deep foundations, which could enlarge the application scopes of bi-directional loading test. A new type of bi-directional loading test for pipe pile was conducted, in which the load cell was installed and loaded after the pipe pile with special connector has been set up. Unlike the conventional bi-directional loading test, the load cell can be reused and shows an evident economic benefit.
文摘The vibration and control of pipes conveying fluid is studied. The solid-liquid coupling vibration equations of the pipe conveying fluid are deduced by Hamilton principle.The direct velocity feedback is used to control the pipe vibration. The whip response and control are discussed.
