Study On Mechanical Properties Of Single Column Footing In Rock Foundation

Most of the mountainous cities of China have good rock foundation conditions,where the major form of foundations is independent foundation under single column footing of the rock.However,the calculation method proposed by the current theory and design specification of the independent foundation under the footing is mainly on the soil foundation,and they cannot truly reflect the bearing capacity of the rock foundation.At the same time,in practical engineering,the independent foundation has certain embedded conditions,and there are relatively few studies on the influence of the lateral constraints of the rock foundation on the foundation force.In order to fully understand the influence of the lateral constraints of rock foundation on the independent foundation,this thesis carried out the in-situ prototype test of the independent foundation under the single column footing of the actual engineering rock foundation,which relies on the basis of summarizing the previous two on-site tests of our research group.Therefore,the base reaction force distribution,lateral pressure distribution and force characteristics of the independent foundation,which locates under the single column footing on the rock foundation and considers the lateral restraint of the bedrock,were investigated,based on the measured and processed data,the elastic theory derivation,and finite element numerical simulation.The main content of this thesis could be divided as follows:1 The experience of related experiments in previous years will be summarized to conduct the onsite test.Then,the prototype test with consideration of engineering practice for the single column footing on rock foundation will be carried out,and the contact pressure and lateral pressure will be measured by placing pressure boxes on the bottom and sides of the foundation.2 Based on the basic working principle and reasonable assumption of elastic mechanics,the Lame analytical solution for circumferential stress and radial stress of the surrounding concrete has been obtained through the inverse derivation,which considers the influence of the lateral constraints of the rock on the foundation and certain embedding conditions of rock foundation.Then,the influence of the lateral constraints of bedrock on the internal force and load bearing capacity of the single column footing has been investigated.Finally,the proposed theory is been validated by comparing the results of theoretical calculation,onsite experiment and numerical simulation.3 The finite element method will be used to numerically simulate the single column footing on the rock foundation with the consideration of lateral constraints,and acquire the stress distribution.Then,the comparison between the simulation results and onsite test results will be raised to validate the proposed theory.