Abstract: Earth pressure coefficient at rest of soil, K0, varies due to different stress conditions. Besides, it interacts with other physical and mechanical properties of the soils. Based on the geological survey of Jinan subway project, the horizontal pressure of the thick alluvial cohesive soil from Yellow River in northwest of Jinan was tested by the in-situ soil pressure tester, K0 stepped blade (KSB). To verify the test results, other test methods are also adopted, such as the lateral loading test, indoor K0 test by side pressure gauge as well as common calculation formula taking internal friction angle and plasticity index of cohesive soil into consideration. According to the comparative analysis of the results by different methods, the results can be obtained as follows. In the form of exponential interpolation, test results from KSB are superior in presuming the in-situ earth pressure coefficient at rest. The cohesive soil in the Yellow River alluvial layer can be approximately in normal consolidation saturated state inside the range of 0-20 m. K0 changes between 0.4 to 0.7 and decreases with the increase of depth. The value of K0 is on the high side with Jaky formula’s result and on the low side with indoor test. The calculation results obtained by Jaky formula are close to that of measured by KSB when introduce equivalent angle of internal friction and internal friction angle obtained by consolidated quick shear test.

Key words: cohesive soil, coefficient of earth pressure at rest, in-situ test, internal friction angle