5 nhungdonggopmoilatienganh ncsngoquoctrinh

SUMARY OF THESIS CONTRIBUTION
Topic of Study: “A study on pile working under horizontal load and seismic load”
Field of Study: Civil and Industrial Construction Engineering
Code: 62 58 02 08
Name of PhD Student: Ngo Quoc Trinh
Supervisors
: Ass. Prof. Dr. Vuong Van Thanh
Dr. Tran Huu Ha
Training Institution:
Hanoi Architecture University
Sumary of Thesis Contribution
1 . Through numerical solution using the finite element method, Kelvin solution about
Mindlin solution can be provided, that means getting the solution of elastic infinite semispace from the solution of elastic infinite space with load placed in any position.
2 . Formulating the static interactive problem, dynamic interaction between piles with
soil under static load, horizontal dynamic load at any position. Using the finite element
method with soil tobe 3-D element, 20 buttons; pile with 2 button elements for displacement
and 3 buttons for shear force to solve. This method automatically satisfies the boundary
conditions at infinity, the soil boundary conditions as well as conditions between pile and
soil, i.e no need to add extra links as springs, viscous box on the contact surface between the
pile - ground, on the border of the land mass storing piles. In addition, the study also
investigates the parameters affecting the work of the piles such as pile length, stiffness of
the pile, piles placed on a layer of hard rock and the effect of piles to the work of the soil.
3. In the calculation of the construction dynamics and earthquake, the viscosity
coefficient is offen considered. In this thesis, the author does not use the ordinary viscosity
coefficient but use the hysteretic damping or dry friction coefficient. This coefficient allows
the consideration of the phenomenon of plastic deformation of the ground when needed .
4. Formulating Love wave problem transmitted from the ground up to soil layer by
considering love waves in the horizontal plane and in vertical plane. Based on the numerical
solution of the finite element method, phenomenon of fluctuating surface amplification
vertically to the wave propagation is studied, consistently with the theory of Love wave
propagation.

5. Formulating the interactive dynamic problem of the pile under the seismic load. Using
the convolution integral Duhamel provides solution in the frequency domain, then Fourier
transform, reverse (IFFT) provides results in the time domain. Use the acceleration map of a
real earthquake (El Centro 1940) as input parameters to survey, identify displacement
parameters, torque, shear force of the pile at any time.
6. Based on Matlab programming language to develop the calculating software program
to serve the case studies and surveys: Mstatic1; Kstatic1; MstaticP1; KstaticP1; KstaticPLs;
KdynaS; KdynaL; KdynaP; KdynaPE.
Hanoi, 5th January 2014

PhD Student

MSc. Ngo Quoc Trinh