CAJ | 학술논문

根据武汉鹦鹉洲长江大桥北锚碇大型圆形沉井结构特点与工程地质条件，结合施工现场沉降监测控制点的实测数据，采用大型有限元计算程序ADINA建立了三维计算模型，对沉井结构及其周围的地下连续防护墙进行了有限元分析，分析了沉井在下沉与封底过程中其结构自身的应力分布与变形情况，并探索了沉井在下沉过程中对周边邻近高层建筑与堤岸构筑物的影响。计算研究结果表明：沉井外围的地下连续防护墙主应力会随沉井的下沉而相应地增加，在沉井封底后其变形主要出现在上部和底部；而沉井在下沉过程中其结构底部的刃脚、十字隔墙、十字隔墙与环形井壁结合处均会出现较大拉应力；沉井的周边土体沉降量会随下沉深度而相应地增大。在沉井封底完成后测点的沉降理论计算值与实际监测值比较吻合，一般计算值较监测值稍小：二者的差值在邻近高层建筑的沉降控制测点为-1.22～-0.88 mm；而在附近的长江大堤处的关键测点为-1.27～0.64 mm。该计算模型对锚碇沉井下沉过程的沉降控制具有参考作用。
근거무한앵무주장강대교북묘정대형원형침정결구특점여공정지질조건，결합시공현장침강감측공제점적실측수거，채용대형유한원계산정서ADINA건립료삼유계산모형，대침정결구급기주위적지하련속방호장진행료유한원분석，분석료침정재하침여봉저과정중기결구자신적응력분포여변형정황，병탐색료침정재하침과정중대주변린근고층건축여제안구축물적영향。계산연구결과표명：침정외위적지하련속방호장주응력회수침정적하침이상응지증가，재침정봉저후기변형주요출현재상부화저부；이침정재하침과정중기결구저부적인각、십자격장、십자격장여배형정벽결합처균회출현교대랍응력；침정적주변토체침강량회수하침심도이상응지증대。재침정봉저완성후측점적침강이론계산치여실제감측치비교문합，일반계산치교감측치초소：이자적차치재린근고층건축적침강공제측점위-1.22～-0.88 mm；이재부근적장강대제처적관건측점위-1.27～0.64 mm。해계산모형대묘정침정하침과정적침강공제구유삼고작용。
Given the structural features and engineering geological conditions of north anchorage large cylindrical caisson of Wuhan Parrot Cay Yangtze River bridges, combining with in-situ monitored data of some key points, three dimensional calculation modes of FEM are established with software ADINA to analyze stress and deformation of caisson structures and its adjacent diaphragm wall. The stress distribution and deformation of the structures are studied during the caisson sinking and its bottom sealing. The effects of caisson sinking on adjacent high-rise buildings and bank structures are also analyzed comparatively. The research results show that: the principal stress of diaphragm wall increases with the increasing of sinking depth, and its deformation appears mainly in its top and bottom after the caisson bottom sealing, the tension stress would be higher at its structure cutting edge, the middle of cross wall, the joints of cross wall and inner face of caisson well. The corresponding settlement of adjacent soil around the caisson increases with the increasing of sinking length as well. Settlements of monitored points from calculation agree well with measured data after bottom sealing, and the former is generally less than the latter. The differences between them are from-1.22 mm to-0.88 mm at the key points of adjacent high-rise buildings, and those at the key points near the Yangtze River bank are from-1.27 mm to 0.64 mm. The calculation model will provide a guide for settlement control during the caisson sinking.