Study On Mechanical Characteristics And Failure Modes Of Single-column Footing On Rock Foundation

Single-column footing is a kind of widely used foundation.At present,there are abundant research achievements in single-column footing on soil foundation,while that on rock foundation are not deep and systematical.Relevant study and calculation both at home and abroad mainly refer to the research results on soil foundation,or make engineering design according to the mechanical properties and failure modes of beam or plate members.Since the stiffness of the soil foundation is small,while the strength and stiffness of reinforced concrete independent foundation are pretty large,the mechanical characteristics of footing are relatively similar to the beam and board members when placed on the soil foundation.Therefore,it is reasonable to design footings on the soil foundation according to the mechanical properties and failure modes of beam and board members.However,compared with the soil foundation,rock foundation has much bigger stiffness,smaller deformation,and higher bearing capacity.When the upper load is large,the difference will be more obvious.With the development of the western development and western mountain town,single-column footing on rock foundation has been more and more popular for high-rise buildings and large municipal transportation of architectural structures under large load.Therefore,a large number of studies have been conducted these years.My tutor's research team has carried out a number of study on the mechanical characteristics and failure modes of single-column footing on rock foundation and put out many innovative achievements,showing that the mechanical characteristics and failure modes of footing on the rock foundation are much more complicated compared to that on the soil foundation.In this paper,the advantages and disadvantages of some mechanical models are compared,and a new mechanical model with broader application condition and more clearly the application range is put out to analyze the mechanical characteristics and failure modes of footing on the rock foundation.And then field test data and numerical simulation analysis are conducted to verify its rationality.The main research content of this paper is as follows:1.Summarize the research status of the mechanical characteristics and failure modes of single-column footing on the rock foundation both at home and abroad.2.Analyze the mechanical characteristics and failure modes of single-column footing on the rock foundation theoretically,and put forward a more reasonable mechanical model.3.Carry out field tests to obtain the counter forces distribution characteristics,internal stress distribution characteristics and the crack development rules of single-column footing on the rock foundation.Then observe and judge the actual failure modes of single-column footing.And finally verify the rationality of the theoretical analysis.4.Carry out numerical simulation and verify the rationality of theoretical analysis combining with experiment results.In this paper,transformation law between base reaction distribution,the failure modes and aspect ratio is obtained through theoretical analysis,field test data and numerical simulation.Then the threshold of aspect ratio is put forward and some useful suggestions are given.The study results of this paper have a certain reference value to the actual engineering.