On the basis of construction of the No.29 open caisson of Hutong Bridge

which is the largest open caisson in the world

in-site monitoring tests were carried out on the entire process of the open caisson construction. By analyzing the monitoring data

it is concluded that results predicted by Rankine’s theory of stationary earth pressure and its normative algorithm are significantly different from the measured data. The result of polyline distribution projection is not satisfactory because there are many influencing factors of lateral pressure and its distribution is complicated. Then

the influencing factors on the size and distribution of lateral pressure during the sinking and subsequent construction of caisson are studied. It is concluded that the main influencing factors of the lateral pressure during the sinking stage and the heightening stage are the slant of caisson

the depth of caisson

the step setting of caisson sidewall and the range of pressure relaxation. The causes and mechanism of various factors are explained based on comparison and analysis.The distribution of lateral pressure along the vertical caisson sidewall and the side frictional resistance calculation model are determined after eliminating the effect of the caisson slant on the lateral pressure of the ultra-deep large and subaqueous open caisson.