On analysis of longitudinal stress of airy pushing tunnel segment of shield in mined method

Taking some subway shield in the airy pushing of the mined tunnel as the background,the paper undertakes the detailed supervision and analysis of the strain process of the segment in the shield construction,sums up the strain law for the segment in the shield construction process,indicates the two obvious steps can be classified of the axial pressure strain of the segment along the time,indicates the strain is increased dramatically at the counterforce stage of the jack and it gradually reduces to the stability,and the side shearing displacement can occur at the partial segment at the grouting stage of the segment's wall back,so the same segment has different lifting of the concrete axial pressure strain,the leakage can happen with the uneven distribution of the strain along the ring direction at the same supervision section,so the general prepressure of the section can meet the demand.