The f-w curve knowing as the curve presents the relationship between the unit shaft friction versus the relative movement between the pile shaft and the soil. The f-w curve is very important to predict pile capacity and settlement of pile and pile group. There are many studies to propose model f-w curve but in Vietnam the research on this issue is limited. In this paper, the authors based on the static load test that installed strain gauges to determine unit shaft friction - displacement of pile segment for some kind of clay in Hanoi and compare with some propose f-w models. The result show that: 1) Almost the authors value, maximum displacement, from experiment is higher than the recommended value of the models
2) For design can use model of Heydinger and O'Neill (1986) and Vijayvergiya (1977) for some kind of clay in Hanoi
3) Can adjust the authors value for clay in Hanoi based on the ratio displacement/pile diameter about 0.6 percent.