Because of different test fundamentals

the bases of judging soil damage with different test methods are also dissimilar; and some test data must be amended with probability statistics; and that cause a rather large otherness among value of subgrade bearing capacity with different test methods and bring a large inconvenience to scientific effort and engineering practice. Since there has a internal relation between the data gathered by different tests and bearing capacity

contraposing different lithologic soil body; regression analysis is used to establish dependency relation between ratio penetration resistance and subgrade bearing capacity

numerical standard penetration and subgrade bearing capacity

interior geotechnic parameters and subgrade bearing capacity; so as to against the otherness in different methods; and that can provide fast and accurate characteristic value of subgrade bearing capacity for expressway surveying and design in the Yellow River delta region.