土层水泥浆预应力锚杆力学分析

上层水泥浆预应力锚杆广泛应用于上层基础加固。锚杆头部主要作用是将拉杆的力传递给建筑物，易于掌握。水泥浆团结体对拉杆的握裹力大小取决于水泥浆质量及拉杆表面的清洁程度与凸凹程度。此类传力方式锚杆没有充分发挥钢筋拉杆的应力，造成锚固段深部上层抗剪应力的浪费，减小锚杆抗拔力。倒拉式锚杆则克服了上述缺点。水泥浆团结体与上层间的作用力对锚杆的极限抗拔力起决定作用，它的大小决定于水泥浆团结体凸体对上层的剪切应力和相对平滑的水泥浆团结体对土层的摩擦阻力。土层蠕变作用限定了锚杆安全系数的取值范围。锚固段要求设置在非重力土楔范围以外的稳定区域。

THE MECHANICAL ANALYSES OF THE SOIL CEMENTATORY SIZE PRESTRESSED ANCHOR BAR

The soil cementatory size prestressed anchor bar has been widely used to consolidate the foundation of soil. The force of the pulling bar is transferred to buildings through the head of the anchor bar. The capacity of the cementatory size in cementing the steel pulling bar depends on the quality of cementatory size, the degree of cleanness and the crudity of the puiling bar's surface, But this process can not make the stress in the steel pulling bar be completely used. This creates a waste of the deep soil shearing stress in the anchored part, and abates the tensile force of a anchor bar. The down-pull anchar bar can overcome these shortcomings. The force of soil to the solidified cementatory size takes decisive effect on the limits of a anchor bar' s tensile force. The limitation value is decided by the shearing stress of all protrusive solidified cementatory size acting on soil and the friction resistant force of all the relatively smooth parts of solidified cementatory size on soil. The value range of safety coefficient depends on the soil's creep process. It is required that the anchored part should be sited in an stable area out of the range of gravity of soil wedges.