Terminal Area Foundation Stability Assessment Of Kunming Newly Built Airdrome

Analysis of foundation stability is the important content of the site selection of project, with the goal to avoid the project construct on the unstable areas. Once the engineering foundation has destroyed, it will cause serious results, especially the large scale engineering project (dam, nuclear power station, airport). So it is aslo the premise of construction of large scale engineering project. Kun-Ming newly built airdrome is located to be the huge hub airdrome now under construction, it is the important project for implementing the big channel witch china oriented towards to southeast asia. Terminal Area as the core of the airdrome, it's foundation stability becomes to be the first priority problem for the airdrome construction. This article takes the statistics and analysis of field material as base, analyses and evaluates the foundation stability of Terminal Area by qualitative and quantitative methods systematically. The main achievement that the essay obtains is as follows:(1) Combines deep loading test results and normal formula method, analyses terminal area foundation's carrying capacity, and draws the Conclusion that: the whole rock foundation's bearing behavior is better, but some of the rock foundation (local layer, Granulitic rocks, mylonite and fault gouge rocks) witch influenced by the F10 fault, it's mechanical properties is relatively worse, and it's bearing capacity relatively low, so it can't meet the design requirements.(2) Conclusions can be made from terrain, landform, geological structure, and rock mass physical mechanical, terminal area foundation is property uneven foundation, and the most hazard of uneven foundation is the uneven sedimentation of building. This is proved by analysis of the experimental results of deep loading test. From the deep loading test's P-S curve can we see that the uneven settlement of rock foundation of terminal area is very obvious, the settlement difference can reach to about two times of the most low settlement.(3)Terminal area foundation as a whole being is divided into two major parts by F10 fault: the foundation effect by fault or not. In the range of effect by fault, the stability of foundation is controlled mainly by all kinds of structure plane. The possible instability mode is shearing-destroy occurred along the direction of structure plane' combination.â‘ The conclusion can be drawn by the analysis of Hoek-Brown's slip-line theory : the stability of terminal area foundation which not effect by fault is well, even load on upper, integral shearing-destroy will not occurred.â‘¡For the rock foundation which effect by fault: Firstly, in terminal area the growth of structure plane was studied, then the mode of possible shearing-destroy was built, finally, the stability of rock foundation was analyzed by rigid body limit equilibrium theory. The conclusion is: Mechanical Property of rock foundation was reduced due to the existence of structure plane, not play a role of controlling. Under the effect of engineering load, rock foundation will not occur shearing-destroy along the direction of structure plane. From above we can come to the following conclusions: terminal area rock foundation no matter effect by structure plane or not, even load on upper, the instability shearing-destroy will not occur.(4) The karst is well developed in terminal area. Based on the analysis of the karst distribution features, the author uses qualitative and quantitative analysis and semi-quantity methods to study and evaluate the stability of terminal area foundation containing karst cave. The results showed that: the ellipse karst cave is easier destroyed than the circular, the cave around by broken rocks are easier destroyed than around by the intact rock mass, most of the karst cove in terminal area are in stable position, but part of the ellipse cave are at non-steady state (in particular near the F10 fault) which will be instable under the loads and then affect the stability of the foundation .(5)The author evaluates terminal area foundation stability through fuzzy comprehensive evaluation form the theory viewpoint.â‘ First of all, in order to evaluate the different regions' foundations in terminal area, pertinently, author divides the whole aera into five subregions, based on the antecedent researches, and consider the factors of landform, physiognomy, geological conditions and the foundation rock and soil's components.â‘¡Secondly, based on the analysis of foundation stability in every subregion and the gradation relations, a assessment model of two stage about terminal aera foundation stability is constructed, which is affected by different factors. And the author put forward the function of every index.â‘¢Finally, based on the comprehensive analysis method for weight detemination, and evaluates the every subarea's stability through the model. The results show that: terminal aera foundation stability is well as a whole, but the foundation of the F10 fault and part of the C₂w strta witch near the F10 fault zone affected by the conformation and dissolution are in relatively stability .