Research On The Methods Of Detection And Evaluation For Inherent Subgrade Of Expressway

During the rapid increase of the total built expressway mileage, early built expressways (such as ShenDa Expressway, HuHangYong Expressway etc.) have been confronted with the extension or heavy repair, because of the debasement of road service level or the increasing traffic. How to detect, evaluate and make use of inherent subgrade has become a very significant problem. This research can provide for the preliminary design and construction documents design. This thesis relies on the subject study of HuNing Subgrade which includes the detection, evaluation and design of the subgrade. All data in this thesis are derived from the project. Firstly, this thesis expatiates on the main idea and then totally explains the process flow of subgrade detection and evaluation. Secondly, this thesis explains the theories and process flows of four kinds of detection methods (such as Earth Probing Radar, Rayleigh Wave, DCP, Probe Drilling). Thirdly, this thesis explains how to process the detection data and deduce the subgrade evaluating indicators. Fourthly, this thesis researches four kinds of evaluating methods (such as Linear-Weighted Evaluating Method, Grey Clustering Evaluating Method, GM(1,1) Predicted Method and BP NN Evaluating Method) and programs with MATLAB6.5, and then this thesis compares the evaluating results with the probe drilling data to prove the effect. At last it makes a briefly summary and points out the original points.