Prediction Of Dissolution Rate Of Building Karst Foundation Along Depth Distribution Function

In this paper,more than 1000 engineering geological data were collected in karst areas,and key projects such as Kunming Airport,Guilin City "one hospital and two museums" and Liuzhou Style Port were used as entry points to thoroughly study the depth distribution law of rock surface dissolution degree in karst areas,the composition ratio characteristics of rock surface dissolution and cavity dissolution in depth direction,and establish These results can provide a reasonable design basis for building foundation in karst areas,and the main research results are as follows:(1)Karst foundation in the depth range can be divided into rock surface dissolution section,composite dissolution section composed of rock surface dissolution and cave dissolution together and cave dissolution section,and these three dissolution sections have certain temporal order;the degree of rock surface dissolution still has the law of exponential decay with increasing depth in the depth range,but for the site with cavernous development,its decay rate is generally higher than the decay rate of the total dissolution degree of the site;When the site is not developed with cavities,only the rock surface erosion section exists;as the development of cavities increases,the thickness of the composite dissolution section will gradually increase,and may become the main erosion area of the site.(2)The rock surface dissolution rate of karst building foundations in karst areas generally has the law of exponential decay with increasing depth,and when it is fitted into the exponential function of elevation,the fitting correlation coefficient can generally reach above 0.90;the rock surface dissolution rate curve has good numerical stability,and when detailed survey is carried out according to the current survey specification,the depth distribution curve of rock surface dissolution rate can generally be well determined,and the curve error is generally within 15%,which has sufficient engineering accuracy.(3)The elevation corresponding to a 75% dissolution rate of the rock surface can be regarded as the predicted value of the upper boundary elevation of the strong dissolution zone of the site,and its prediction error is generally within 0.5m;for karst sites with less strongly developed cavities,the elevation corresponding to a 15% dissolution rate of the rock surface can be taken as the predicted value of the lower boundary elevation of the strong dissolution zone;the prediction curve of the depth distribution function of the site dissolution rate can be obtained from the upper limit elevation and lower limit elevation of the strong dissolution rate predicted by the depth distribution curve of the rock surface dissolution rate,and the prediction result is more reliable.(4)The prediction curve of the depth distribution of dissolution rate obtained according to the prediction control standard of 30% dissolution rate is mostly in line with the actual engineering situation,and the prediction error of the prediction curve in the depth range of the strong dissolution zone is generally less than 15%,which meets the accuracy requirements in engineering practice.(5)The statistical calculation workload of engineering data in this thesis is large and the processing steps are tedious.For this reason,the dissolution rate data processing software has been developed in java language,which simplifies the statistical processing of data in the research process of the thesis.