中文摘要：

预应力混凝土倒虹吸结构是一个受力状况复杂的大体积混凝土结构，在温度变化作用下，其应力状态难以确定。为此，运用三维有限元对倒虹吸结构进行了数值分析，确定其在无温度变化、最大温升、最大温降情况下9种工况的应力分布状态。结果表明，在各种设计工况荷载作用下，无温度变化时，预应力混凝土倒虹吸结构均没有产生拉应力；但在温度变化时，工况I和工况Ⅲ均产生了较大的拉应力。其中，在温升情况下，工况I底板下表面和工况Ⅲ顶板上表面产生拉应力大小分别为1．53MPa和1．72MPa在温降情况下，工况I边墙内侧、工况Ⅲ顶板下表面、工况Ⅲ底板上表面和工况Ⅲ边墙内侧产生拉应力大小分别为1．36MPa、1．77MPa、1．85MPa和1．65MPa。因此，温度变化对倒虹吸结构的影响是不容忽视的。

英文摘要：

The structure of prestressed concrete inverted siphon is a large-volume concrete structure with complex stresses, and the stress is difficult to be ascertained when the structure is affected by changing temperature. The structure of inverted siphon was analyzed using 3-D finite element method（FEM） to obtain the stress distributions under nine working conditions including no change of temperature, maximum temperature rise, and maximum temperature drop. The results showed that under several working conditions, the structure of prestressed concrete inverted siphon did not produce tensile stress with no change of tem- perature. The large tensile stress were produced under the working conditions I and III with temperature changes. Under the condition of temperature rise, the tensile stress was i. 53 MPa and 1.72 MPa, respectively, in the bottom surface of base plate for condition I and the top surface of apical plate for condition III. Under the condition of temperature drop, the tensile stress was 1.36 MPa, 1.77 MPa, 1.85 MPa, and 1.65 MPa, respectively,in the sidewall for condition I,in the bottom surface of apical plate for condition III,in the top surface of base plate for condition III, and in the sidewall for condition III. Therefore, tempera- ture changes had significant impacts on the structure of inverted siphon.