Density identification method of dam foundation deep overburden is put forward. The Weibull distribution model is established based on 8 holes

106 points field pressuremeter tests in dam foundation deep overburden of Shuangjiangkou Hydropower Station. Parameters of the distribution are estimated by least-squares method based on the test results above; and the goodness-of-fit of Weibull distributions is tested. The corresponding relations among pressuremeter modulus

density and pressure are investigated by 20 sets of model tests using the given grading curve acquired in field exploration. The exponential relation of pressuremeter modulus and density is determined by model tests. Based on those above

the authors carry out randomly numerical simulation of the density of dam foundation deep overburden. The simulated density of second-overburden is obtained and its practicability is proved through comparing with exploration results