| The existing soil anchors are mostly equal-diameter soil anchors.In order to improve the bearing capacity of the soil anchors,this paper proposes a multi-horizontal soil anchor and its forming tool.In order to explore the bearing capacity characteristics of multi-horizontal soil anchors,numerical simulation software is used to analyze and study the horizontal bearing capacity,maximum pull-out displacement,side friction resistance and anchoring mechanism.(1)In order to form the transverse cavity of multi-horizontal anchors,use special tools to drive the screw rod through the reducer,the screw rod to drive the pressure block,the pressure block presses the soil in the radial direction of the borehole,and changes the position to form multiple horizontal cavities.After entering the steel strand and pouring the cement mortar,a multi-horizontal soil anchor will be formed after solidification.This tool is suitable for a hole diameter of 150mm,the lateral depth of the transverse bolt is 100mm,and the thickness of the transverse bolt is 80mm.(2)Firstly,the theory of interaction between transverse bolts and soil is analyzed,and secondly,by analyzing known theoretical formulas and methods of calculating bearing capacity,such as technical specifications for building foundation pit support(JGJ120-99),"Rock and Soil Anchorage","British Standard BS8081",Swedish ATALS method,etc.,explored and analyzed the anchoring mechanism of multi-horizontal soil anchors in soil from the level of theoretical knowledge.(3)By using FLAC3D numerical simulation software,the factors affecting the bearing capacity characteristics of multi-horizontal soil anchors were studied.Because the parameters of the transverse bolts are the main factors affecting the bearing capacity,a total of 17 groups of models were established to study the ultimate anti-pull characteristics of the transverse anchors,including the distribution of transverse bolts,the thickness of the transverse bolts,the net spacing between the transverse bolts,and the number of transverse bolts.Impact.According to the rising trend of its bearing capacity and the trend of displacement change,the optimal cross bolt spacing is 330mm(2.2d),the optimal number of cross bolts is 12,the optimal cross bolt thickness is 80mm,and the distribution of cross bolts that best meets the force law is Asymmetric distribution.(4)By using FLAC3D numerical simulation software,the similarities and differences between the main indicators such as the horizontal displacement,ultimate pull-out bearing capacity,side friction resistance and axial force of multi-horizontal bolts in the horizontal direction are compared and analyzed with ordinary anchors.The length of 5m,diameter of 150mm,net spacing between transverse bolts is 330mm,and the ultimate bearing capacity of multi-horizontal soil anchors with a buried depth of 5m is 247kN.The transverse bolts bear 64%of the total load,which is the same as ordinary anchors of the same section under the same load Compared with the rod,the bearing capacity of the multi-cross bolt is increased by 55%.(5)Under the conditions of various optimal parameters,by analyzing the results of numerical simulations,according to the interaction relationship between the multi-horizontal anchors and the soil body in the displacement cloud diagram,the multi-horizontal anchors and soil body under load are studied.The range of influence when interacting.When the load is 247kN,the stress diffusion shape of the multi-horizontal anchorage with a length of 5m is elliptical from the cut surface,the long axis of the ellipse is 5m,and the short axis is 2m(6)In order to study the bearing capacity characteristics of multi-horizontal soil anchors under different lengths and burial depths,the load-displacement curve is drawn to explore its variation law.The ultimate bearing capacity increases with the increase of the length,but due to the side frictional resistance between the anchor rod and the soil,the load that can be transmitted to the lower part of the soil anchor is limited when the multi-horizontal soil anchor is loaded.When the length is increased to a certain level,the effect of increasing the length on the bearing capacity is not obvious.However,with the increase of the burial depth,the ultimate bearing capacity of multi-horizontal soil anchors increases,and the increase is also getting larger.Due to the increase in the upper soil of the soil anchor,the stress on the multi-bolt soil anchor increases,and the density of the deep soil increases at the same time,which increases the side friction resistance and end bearing capacity,thereby increasing the ultimate bearing capacity.Figure[34]Table[9]Reference[58]... |
PDF Full Text Request