为了解大直径地铁盾构隧道衬砌结构的受力性能，基于广州轨道交通4号线南延段大直径地铁盾构隧道工程，采用水土压力计和钢筋应力计传感器对衬砌结构运营期间的外荷载和钢筋应力进行现场测试，得到衬砌结构外荷载和内力的响应规律。通过衬砌结构计算模型理论值与现场测试结果的比较，说明衬砌结构计算模型的合理性。研究结果表明： 1）衬砌结构顶部的水土总压力实测值和上覆土柱的重力基本一致； 2）衬砌结构底部的水土总压力呈现中间小、两边大的分布形态，计算模型中可在衬砌结构下部半圆周范围内布置土弹簧模拟衬砌结构的实际受力情况。

Taking the largediameter metro shield tunnel on the south extension line of Guangzhou Metro Line No. 4 for example, the external load and internal force response principle of lining structure in operation phase are obtained by field test of external load and reinforced bar stress of lining structure monitored by sensors of waterearth pressure gauge and reinforced bar stress gauge. The rationality of the calculation model of lining structure is illustrated by comparison between the theoretical value of the model and the field test results. The study results show that: 1） The total pressure of soil and water on top of tunnel coincides with the weight of overlying soil column. 2） The total pressure of soil and water at the bottom of the tunnel is small at middle section and those are large on both end; therefore soil springs can be arranged in the lower half circle of the lining structure to simulate the actual stress in the calculation model. 