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杯口基础要点
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《建筑地基基础设计规范》GB50007-2010 |
EN1992-1-1 |
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8.2.4预制钢筋混凝土柱与杯口基础的连接（图8.2.4），应符合下列规定：
图8.2.4 预制钢筋混凝土柱与杯口基础的连接示意 注：a2≥a1；1-焊接网 1 柱的插入深度，可按表8.2.4-1选用，并应满足本规范第8.2.2条钢筋锚固长度的要求及吊装时柱的稳定性。 表8.2.4-1 柱的插入深度h1(mm)
注：1 h为柱截面长边尺寸；ha为双肢柱全截面长边尺寸；hb为双肢柱全截面短边尺寸； 2 柱轴心受压或小偏心受压时．h1可适当减小，偏心距大于2h时，h1应适当加大。 2 基础的杯底厚度和杯壁厚度，可按表8.2.4-2选用。 表8.2.4-2 基础的杯底厚度和杯壁厚度
注：1 双肢柱的杯底厚度值，可适当加大； 2 当有基础梁时，基础粱下的杯壁厚度，应满足其支承宽度的要 求； 3 柱子插入杯口部分的表面应凿毛，柱子与杯口之间的空隙，应 用比基础混凝土强度等级高一级的细石混凝土充填密实，当达到 材料设计强度的70%以上时，方能进行上部吊装。 3 当柱为轴心受压或小偏心受压且t/h2≥0.65时，或大偏心受压且t/h2≥0.75时，杯壁可不配筋；当柱为轴心受压或小偏心受压且0.5≤t/h2＜0.65时，杯壁可按表8.2.4-3构造配筋；其他情况下，应按计算配筋。 表8.2.4-3 杯壁构造配筋
注：表中钢筋置于杯口顶部，每边两根（图8.2.4）。 |
10.9.6 Pocket foundations 10.9.6.1General (1)P Concrete pockets shall be capable of transferring vertical actions, bending moments and horizontal shears from columns to the soil. The pocket shall be large enough to enable a good concrete filling below and around the column. 10.9.6.2 Pockets with keyed surfaces (1) Pockets expressly wrought with indentations or keys may be considered to act monolithically with the column. (2) Where vertical tension due to moment transfer occurs careful detailing of the overlapreinforcement of the similarly wrought column and the foundation is needed, allowing for the separation of the lapped bars. The lap length according to 8.6 should be increased by at leastthe horizontal distance between bars in the column and in the foundation (see Figure 10.7 (a) )Adequate horizontal reinforcement for the lapped splice should be provided. (3) The punching shear design should be as for monolithic column/foundation connections according to 6.4, as shown in Figure 10.7 (a), provided the shear transfer between the column and footing is verified. Otherwise the punching shear design should be as for pockets with smooth surfaces. 10.9.6.3 Pockets with smooth surfaces (1) The forces and the moment may be assumed to be transferred from column to foundation by compressive forces F1, F2 and F3 through the concrete filling and corresponding friction forces, as shown in Figure 10.7 (b). This model requires l≥ 1,2 h. (2) The coefficient of friction should not be taken greater than µ = 0,3. (3) Special attention should be paid to: |
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– detailing of reinforcement for F1 in top of pocket walls.
(a) with keyed joint surface
(b) with smooth joint surface Figure 10.7: Pocket Foundations
– transfer of F1 along the lateral walls to the footing – anchorage of main reinforcement in the column and pocket walls – shear resistance of column within the pocket – punching resistance of the footing slab under the column force, the calculation for which may take into account the insitu structural concrete placed under the precast element. |
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欧洲杯壁基础计算简图
欧洲规范对杯壁的计算可以由上述简图推导出来。
规范虽然差不多，但还是有不同。
