CAJ | 학술논문

为探讨钢板桩围堰体系工作特性,通过建立双排钢板桩围堰体系弹塑性有限元数值模型,采用基于Mohr-Coulomb破坏准则的理想弹塑性本构模型考虑土石物的弹塑性性质,采用罚函数接触算法描述界面接触特性,针对不同水位下钢板桩围堰在加载过程中呈现的受力变形特征进行了分析与讨论.计算分析表明:在高水位时外侧钢板桩承受被动土压力,而在低水位时外侧钢板桩承受主动土压力.在极端高、低水位情况下,围堰土石体系均在拉杆内侧端部附近区域存在明显的塑性区,在极端低水位下拉杆外侧端部土石体系附近区域也存在明显塑性区.围堰外水位越低,围堰外侧钢板桩承受的主动土压力越大,外侧钢板桩的正向侧向变形亦越明显,拉杆和钢板桩强度特性发挥的越充分.因此,随着围堰外水位标高增加,拉杆截面正应力变化率呈现逐渐衰减变化特征.
위탐토강판장위언체계공작특성,통과건립쌍배강판장위언체계탄소성유한원수치모형,채용기우Mohr-Coulomb파배준칙적이상탄소성본구모형고필토석물적탄소성성질,채용벌함수접촉산법묘술계면접촉특성,침대불동수위하강판장위언재가재과정중정현적수력변형특정진행료분석여토론.계산분석표명:재고수위시외측강판장승수피동토압력,이재저수위시외측강판장승수주동토압력.재겁단고、저수위정황하,위언토석체계균재랍간내측단부부근구역존재명현적소성구,재겁단저수위하랍간외측단부토석체계부근구역야존재명현소성구.위언외수위월저,위언외측강판장승수적주동토압력월대,외측강판장적정향측향변형역월명현,랍간화강판장강도특성발휘적월충분.인차,수착위언외수위표고증가,랍간절면정응력변화솔정현축점쇠감변화특정.
Aiming at discussing the working performance of cofferdam system with steel sheet piles, nonlinear numerical computation is conducted in the present work by developing elasto-plastic FE model in plane stress state, employing Mohr-Coulomb yield criterion to describe the elaso-plasticity of subsoil and Coulomb contact pair theory with penalty algorithm to simulate the discontinuous con-tact behavior between foundation and soil, as well as using infinite element in model boundaries to a-void static boundary effect. The numerical results show that the outer sheet pile bears passive earth pressure at higher water level and active earth pressure at lower level. Plastic zone exists in the earth and stone of cofferdam system near the inner end of tensional rod at both maximum and minimum water levels. Differently, plastic zone only lies near the outer end of tensional rod at minimum water level in the earth and stone of cofferdam system. The lower water height is, the more active pressure and positive lateral deformation of outer steel sheet pile are. Due to the augment of exerting suffi-ciency with the increase of water height level for the strength of tensional rod, the variation ratios of normal stress of tensional rod section display decreasing characteristics.