Study On Soil Pressure Of Culvert With Different Shapes

The culvert which is a kind of buried construction is widely used in water conservancy and other industries,with the blossom of our country’s economic, large engineering projects such as the South-to-North Water Transfer Project need to use lots of culverts, embankment height is higher and higher as well. The great soil pressure is more likely to break the culverts, more exposed the earth pressure culvert calculation standard in use and calculation formula of the defects and the insufficiency. Culverts engineering has been known as "the lifeline engineering", But at present, the culvert design and construction of relevant disciplines is still very imperfect, tend to be poorly designed cause disease, so earth pressure on culverts theories still need further research. In ref.[46,47] in this paper, the physical model test results are analyzed in detailed, and the test results compared with the ANSYS finite element software simulation results, was coincident, and ANSYS is proved the feasibility of the software used for simulating the interaction of soil and culvert. Select a highway arch culvert engineering example, the use of the filled soil and the culvert parameters, and design three different hole type contrast research, the main results are as follows:(1)The height of He is not constant, He decreases with increasing of the height of embankment fill, different culvert type will affect the settlement of erath fill and change the height of He. Under the rigid foundation, the He of box culvert, arch culvert (rise-span ratio=1/2and1/4) are3.1D and2.9D and2.7D sepreately. The foundation stiffness is smaller, The height of He is lower, other culvert foundation stiffness, box culvert’s Heis more likely to effected by the foundation stiffness.when the foundation stiffness is400mpa, three culverts’He height is very close to the He of rigid foundation.When (3=5, the He of the3kinds of culverts are1.9D,1.8D and1.7D,when P=20, the He approximately equal to He under rigid foundation.(2) Earth pressure distributions are not the same when the culvert shape is different. Box culvert’s pressure distribution curve in the middle on the concave and convex on the "M" shape on both ends of the distribution; rise-span ratio=1/2and1/4arch culverts’pressure distribution are inverted "U" shape, semicircle arch culvert is apart from the hole axis of0.35D outside the vault has no earth pressure concentration. (3) Three shapes of culverts under rigid foundation on average coefficient of earth pressure along with the increase of filling soil height are stable, box culvert is1.6, rise-span ratio=1/2and1/4arch culverts are1.4,1.26. Arch culvert vault and arch plane earth pressure is not the same, the research should be explained;Kd is88%of Kp.Decrease the foundation elastic modulus can effectively reduce the earth pressure concentration on the top of box culvert When β=20,K of the box culvert is20%less than the K under rigid foundation.