Analysis Of Stress Field Of Rock Surrounding Reinforced Concrete Filled Steel Columns Based On Damage Theory

With the rapid development of population and economy, the demands of quantity and quality for water are increasing rapidly. The impacts of human activities on water pollution made that many countries and areas have arisen water resources. China and other countries have built many concrete filled steel tube columns to relieve the problem. Because the natural stress field is changed due to tunneling roadway, a stress concentration area appears in rock of surrounding roadway that cause roadway deformation or destruction. Therefore, the calculation of the stress field and displacement field of rock surrounding roadway must be reasonable and accurate; it can provide a theoretical foundation for the calculation of deformation or destruction and stability analysis of roadway. A lot of micro-crackle exists in rock mass; the macroscopically mechanical properties of rock material depend on its emerging, expanding and combining determines. So the rock damage property must be considered. Groundwater is the important factor of rock occurrence. The impacts of seepage field on stress field and displacement field peripheral to the underground tunnel are existing anytime, especially the deeply buried high head groundwater and high head reinforced concrete filled steel tube columns. The impacts of seepage field on stress field and displacement field peripheral to the underground tunnel are unneglectable.In order to clarify the influence of the groundwater seepage and the rock damage property on the stability of the rock surrounding reinforced concrete filled steel columns, this article presents reinforced concrete filled steel columns, as porous medium, and rocks are affected by ground water permeation. The luid-solid coupling theory, elasto-plastic theory and damage mechanics, unified strength theory are used, the equation to stress field and displacement field is deduced according to different in-situ stress states. The impacts of internal friction angleφand cohesion c on stress field and displacement field are obtained under different in-situ stress states based on an example.The effects ofφand c on the radius, the stress and displacement of the damage zone surrounding rock and the complete damage zone are same. When the rock appeared damage zone, the effects ofφon the damage radius are significant. With the increasing ofφthe damage zone gradually decreases. It has the same law when the rock appeared complete damage zone. But the latter is more significant. When the rock appeared damage zone, the effects of c on the damage radius are not so notable. With the increasing of c the damage zone gradually decreases. It has the same law when the rock appeared complete damage zone. But the former is more significant. In this paper, if the influences of intermediate principal stress, ground water permeation, different in-situ stress states and the rock damage property are not considered, the results can degrade to considering damage or groundwater seepage. So the results of the article have a widespread application.