Experimental Research On Basic Behavior Of Fiber Concrete And Model Pile Under Horizontal Load

As China's construction industry matures,concrete,as a universal engineering material,its application is more and more widely.And its tensile properties is weak,brittle and so on,so it has been unable to fully meet the requirements of the building for strength and deformation,especially in the basic engineering and foundation pit engineering.With the increasing height of the building,foundation and supporting pile often need to bear greater horizontal load,which put forward higher requirements for construction and design.With the successful bidding of 2022 Winter Olympics in Beijing,the development of Zhangjiakou area has been greatly promoted.The reconstruction and construction of the old urban areas and development zones have entered a new phase in full swing.Under this background,ordinary concrete materials can not be completely meet the needs of project and it should be improved to ensure that the project would be more safe,reasonable and affordable.In order to explore the improvement effect of fiber applied in concrete piles,basalt fiber with different length and different shapes of steel fiber were selected in this paper,which were mixed into concrete to carry out uniaxial compression test and splitting tensile test.After that,the optimal fiber was selected to make the fiber-reinforced concrete model pile,and the model pile which is under horizontal load was tested under the existing conditions.The main findings are as follows:(1)Both basalt fiber and steel fiber have a certain influence on the slump of concrete,and basalt fiber has a greater influence.The results of conventional tests show that the two fibers have a lower increase in the compressive strength of concrete and a significant increase in the tensile strength.The optimum amount of basalt fiber is 3 kg/m3 and the optimal length is 18 mm.The optimal type of steel fiber is hook type,and the optimal tensile strength is 50kg/m3.Both the length of basalt fiber and the shape of steel fiber have a significant effect on the strength of the concrete.At the same time,both fibers increase the integrity of the concrete to a certain extent.(2)The test results of model piles under horizontal loads show that the horizontal load-carrying properties of SFRC piles are significantly better than those of plain concrete piles.The incorporation of steel fibers effectively relieves the pile top displacements and piles during the horizontal loads.The deformation of the body and the earth pressure on the pile side did not change the stress distribution of the pile.At the same time,the fracture position of the pile was basically at the same position of the depth of the soil,but did not move down due to the increase of the depth of soil insertion,indicating that the upper soil was on the pile.Larger role...