Master Dissertation Of Suzhou University O Science And Technology Experimental Study On Anchorage Effect Ofmulti-bar Reinforced Concrete Reinforcedstructure

Chemical planting reinforcement technology is one of the commonly used reinforcement technologies in our country,but at present,the pull-out test of single reinforcement or double reinforcement is mostly used in the experimental research at home and abroad;however,in practical engineering,due to the limitation of component size and other requirements,the embedded depth of planting reinforcement often does not meet the design requirements,so the multi reinforcement planting method is needed.The stress of multi bar planting is more complex than that of single bar planting.Due to the limitation of spacing or edge distance,multi bar planting leads to the overlapping of each reinforced concrete cone,which leads to the reduction of bearing capacity.In order to study the influence of anchorage depth,number of planting bars,planting bar edge distance and planting bar spacing on the bearing capacity of multi bar planting,the following three aspects are studied in this paperIn order to analyze the group anchor effect of multi bar planting,four single bar planting specimens corresponding to the embedded depth of multi bar planting were set up,a total of 19 bar planting specimens were set up.The pull-out test of 19 bar planting specimens was carried out,and the load displacement curve and the load displacement curve of each specimen were measured According to the load displacement curve of the concrete surface,the influence of various parameters on the multi reinforcement group anchor effect is analyzed;the experimental study shows that the group anchor effect decreases with the increase of the spacing and edge distance of the planting reinforcement,increases with the increase of the number of planting reinforcement,and the buried depth of the planting reinforcement has little influence on the group anchor effect.At the same time,the expression of the influence coefficient of the spacing and the edge distance on the bearing capacity of multi bar planting is derived;In this paper,through the finite element analysis software ABAQUS,the nonlinear spring element spring2 is established between the glue and the concrete to simulate the bond slip relationship between the glue and the concrete.The feasibility of the model is verified by modeling the test model and comparing with the test results.By establishing 23 specimens with the same buried depth and different spacing,the buried depth of the rebar is analyzed The finite element simulation shows that the group anchor effect will decrease with the increase of the buried depth when the buried depth is between 6d and 10d;the buried depth has little effect on the group anchor effect when the buried depth is between10 d and 12 d.Based on the experimental study,finite element simulation study and the calculation expression of single reinforcement composite failure bearing capacity,the influence of multi reinforcement planting edge distance and multi reinforcement planting spacing on multi reinforcement planting bearing capacity is considered,and the calculation formula of multi reinforcement planting bearing capacity is derived.The calculation results show that the calculated value is in good agreement with the experimental value.