Research on Application of New Standard Penetration Test in Tianjin Metro Project

The standard penetration test (SPT) has the advantages of simple equipment, convenient operation, wide adaptability of soil survey. But it cannot effectively test the energy transferred to the standard penetration device. To effectively test the energy, a new standard penetration device is proposed and was used in a metro project in Tianjin to test the physical and mechanical parameters of soil in the field. Based on the field test results, the relationship between the blow count and the test energy index was explored. And the method to calculate the soil physical and mechanical parameters, such as bearing capacity of ground, soil strength parameter and modulus, is established based on the test energy index from the new standard penetration test. It provides an important basis for the promotion and application of the new standard penetration test.