| Based mainly on the subject "Testing Study on Bearing Proper-ties of Pi le Foundation In Xigeda-rock" and "Study on Work Proper-ties of Slide-resist ant Pile In Xigeda-rock" under the western traff-ic scientific research project "Research on Highway Construction Techniques in Xigeda-rock "and refering to already existing research informations of pile in Xigeda-rock, this thesis sy -stematicly study the horizontal bearing properties of cast-in-place pile in Xig eda-rock by laboratory soil test , static load test on the field,and theoreticalcalculation.Firstly, based with the data of laboratory soil test and excavation on the field of two circular test piles in Xinjiu of Pa-nzhihua and two rectangle testpiles in Anning River Valley, the author analysis Xigeda-rock: Although has beared certain amount of becoming the rock function, its degree of becoming the rock function-n is different to the rock before the fourth department.so itsstrength is lower. This rock would weathering when exposed to the air longtime and would lead to capacity declined.Secondly, the moment and soil resistance of pile increase gradually alongthe top of pile to deep place and they would become maximum value at ab -out two or three times diameter of pile under the ground.Following they wo ulg rapid reduce when the depth go on increasing.But the moment and soil resistance still exist at more deep place .Their distribution forms are similar to the horizontal bearing properties of pile in sandy soil foundations. Their di -stribution forms are different from pile laid in the rock. Moreover, we knewthat the soils of upper part are the main function to the maximum values ofmoment and horizontal soil resistance by analysising their regulation in Xige da-rock.Thirdly, using the different distribution forms of foundation coefficient "m" method and Constant method, calculated the internal force of test piles. The results show that : (1) Although the intensity and characteristics of test piles are different in Xinjiu of Panzhihua and Yonglang of Anning River Vall -ey ,its show the same rules in "m" method calculation. So "m" method adap -t in the two regions. Though moment and distance calculated in Constant method can fit with actually measure, the soil resistance distribute is differentfrom actually measure. (2) The value of "m" is 30MN/m~4 and 110 MN/m~4 Calculated in "m" method in Xinjiu and Yonglang. Referencing the "Foundations of the Highway Bridge Design Specification " (TJT 024-85) , m equal 30MN/m~4 including to hard or semi-hard clay, coarse sand foundation coeffici -ent, and m equal 110 MN/m~4 including to compact sand-cobble,cobstone foundation coefficient.So horizontal resistance characteristic of Xigeda-rock in Xin -jiu is equal with hard plastic clay, and horizontal resistance characteristic of Xigeda-rock in Yonglang is equal with compact sand-cobble,cobstone. (3) When use "m" method in Xigeda-rock, "the top of pile is free, and the end of pile lay in non-rock or lay on the rock" are more realistic assumptions. (4) It can get different "m" under different loads and sections experiments.Finally, the author calculated test pile using FLAC software. The piles a dopting elastic model and Xigeda-rock using Mohr-Coulomb constitutive mode -1 when calculate using FLAC software .The results of calculation certain deg -ree reflects the test results. It seems that the finite difference method calculat -ing the horizontal bearing pile as aided design tool is proper.
|
PDF Full Text Request