Research On Theory And Application Of A Buildings Inclination Rectification Digging Hole With Flower Shape

In the buildings inclination rectification project,the digging-hole rectification method was the most commonly used,and the traditional digging hole mostly were circula.However,the traditional digging-hole method may not achieve the desired rectification effect,especially the foundation soil that after the long-term effects of the load the soil mechanical properties and stress distribution of the foundation soil became complex.Using the small-diameter digging hole,it was not easy to collapse the digging hole.When the diameter of the digging hole was increased,it was easy to over-tilt.It was more difficult to realize the controllably,rapidly and precisely builgings rectification.In order to solve the above problems,a new type of digging-hole with a symmetrical flower-shape rectification method was proposed in this paper.This type of digging hole was characterized by a small circle-shaped convex section with a radius of symmetry,and the ratio of the radius of the big circle and the radius of the small circle can control the stress concentration in the soil.When the diameter of the new type digging hole was smaller diameter or the number of digging hole was less,the new type digging-hole also could realize the much better rectify effect.The article mainly includes the following research contents and new achievements:(1)A method of rectification with a flower shape digging-hole was proposed,and an adapted hole-forming device was designed.The utility model patent of A hole forming device of a new type digging hole with flower shape was authorized.The feature of the hole-forming device with flower shape was that the cross-section of the digging hole contained a symmetrical flower earring circula,which can artificially control the stress concentration in a certain region of the soil.It could effectively solved the problem of using a smaller diameter digging hole that can’t be collapsed,could realize the controllably,rapidly and accurately rectification effect;(2)In response to this new type of digging hole with flower shape,the boundary conditions of elastic mechanics and Saint-Venant’s principle were used and the approximately calculation formula of the stress concentration factor near the point A in the horizontal digging hole with flower shape was deduced.The numerical calculation method verified that when the ratio of the great circle radius R and the small circle radius r was within the range of 1 to 6,the stress concentration factor at the point A of hole wall of the digging hole with flower shape calculated by theapproximately formula and the error between the result of the approximately foumula and the result of the actual condition was smaller.With the increasing of the ratio of R/r,the stress concentration factor at point A increases gradually.A paper of The hole wall stress analysis and engineering application of inclination rectification digging hole with flower shape was published in the Mechanics and Practice.(3)According to the project example,the approximately calculation formula of the stress concentration factor near the point A in the vertical digging hole with flower shape was deduced.Using the numerical calculation method,the relationship between the hole distance D and aperture d of this new type digging hole was calculated,and the stress concentration factor and the stress values of the soils in the two adjacent digging hole with flower shape were calculated under different hole distance.It was concluded that there were plastic zones in the middle soil of two adjacent digging holes when the hole distance D(27)12d.According to the load-displacement(p-s)curve,the formula between the depth of the hole and the soil load under the base was deduced,which provided the basis for engineering design.(4)Using the numerical calculation software Flac 3d to analyze the displacement of foundation soil,under single-row vertical digging hole with flower shape and double-row vertical digging hole with flower shape.It was determined that the double rows of vertical diggign hole with flower shape in the process of building rectification have a much greater effect on improving the deformation of the underlying soil.After a comparative analysis of the triangular layout scheme the displacement was much more than the square layout scheme.Through the practical application of an engineering example,this kind of digging hole with flower shape soil rectification program has achieved a better practical application effect.