Study on the Design Method of Prestressed Reinforced Concrete Beams Subjected to Torsion

预应力钢筋混凝土受扭梁设计方法研究

• 批准号: 01550380
• 负责人: KOJIMA Takayuki
• 金额: $ 1.28万
• 依托单位: Ritsumeikan University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1989
• 资助国家: 日本
• 起止时间: 1989 至 1990
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-01550380/
• 关键词: Torsion; Prestressed Reinforced Concrete Beam; Ultimate Torque; Cracking Torque; Shear Flow; Effective Area of cross section for torsion; Effective Prestress; Prestress Factor; プレストレス鉄筋コンクリ-ト部材; プレストレスト鉄筋コンクリ-ト; 有効プレストレス量; 正負交番純ねじり

The ultimate torque of prestressed reinfored concrete beams subjected to pure torsion was investigated especially by focussing on the shear flows (q_1 and q_w) of longitudinal steel and stirrup at the ultimate state, steel ratios (p_1 and p_w), prestress, and the effective area of cross section for torsion. The following results can be drawn.1. The ultimate torque increased with the amount of prestress even in the prestressed reinforced concrete beams with large section, where the shear flows at the ultimate state (q_1 and q_w were nearly same, and the steel ratio (p_1 and p_w of longitudinal steel and stirrup were also same.2. The strain of prestressing bar at the ultimate torque was almost same as that of prestressing bar tensioned at the prestressing. Although the strain of prestressing bar increased under the repeated load after the ultimate torque, torque, torque did not increase. The ultimate torque calculated by JSCE method assuming that prestress disappears at the ultimate state, therefore, overestimated that of the prestressed reinforced concrete beam, especially when the prestress was small.3. From the results of 1 and 2, prestress should be taken into account in calculating the ultimate torque of prestressed reinforced concrete beams.4. The strain of high-strength stirrup was very small at the ultimate torque. High-strength stirrup does not resist the torsion effectively.5. The effective area for torsion remarkably influences on the ultimate torque, especially when the cross section of beam was relatively small.

研究了预应力钢筋混凝土梁在纯扭作用下的极限扭矩，重点考察了极限状态下纵筋和箍筋的剪力流（q_1和q_w）、配筋率（p_1和p_w）、预应力和截面有效扭转面积。可以得出以下结果。1.即使是大截面预应力钢筋混凝土梁，其极限扭矩也随着预应力的增加而增加，极限状态下的剪流（q_1和q_w）基本相同，纵筋和箍筋的配筋率（p_1和p_w）也基本相同.预应力筋在极限扭矩下的应变与预应力筋张拉时的应变基本相同。在反复荷载作用下，预应力筋的应变虽然有所增加，但在极限扭矩、扭矩、扭矩没有增加。采用JSCE法计算的极限扭矩假设预应力在极限状态消失，因此高估了预应力钢筋混凝土梁的极限扭矩，特别是当预应力较小时.由1和2的结果可知，在计算预应力钢筋混凝土梁的极限扭矩时应考虑预应力的影响.高强度螺栓在极限扭矩下的应变很小。高强度螺栓不能有效地抵抗扭转.扭转有效面积对极限扭矩的影响很大，特别是当梁截面较小时。

项目成果

児島 孝之: "大断面を有するPRC部材の終局純ねじり耐力に関する研究" コンクリ-ト工学年次論文報告集. Vol.13. (1991)

小岛贵之：“大截面PRC构件的极限纯扭转强度研究”《混凝土工程年报》第13卷（1991）

Takayuki, KOJIMA: "Study on the ultimate torque of prestressed reinforced concrete beams subjected to pure reversed torsion" Transactions of the Japan Concrete Institute. Vol. 12. (1990)

Takayuki, KOJIMA：“纯反向扭转作用下预应力钢筋混凝土梁极限扭矩的研究”日本混凝土协会汇刊。

児島 孝之: "純ねじりを受けるPRC部材の終局耐力に関する一実験" コンクリ-ト工学年次論文報告集. Vol.11,No.2. 363-368 (1989)

小岛贵之：“纯扭转下 PRC 构件极限强度的实验”《混凝土工程年报》第 11 卷第 2. 363-368 期（1989 年）

児島孝之: "純ねじりを受けるPRC部材の終局耐力に関する一実験" コンクリ-ト工学年次論文報告集. 第11巻-第2号. 363-368 (1989)

Takayuki Kojima：“纯扭转下 PRC 构件的极限强度实验”《混凝土工程年报》第 11 卷第 2. 363-368 (1989)。

児島 孝之: "PRC部材の終局純ねじり耐力に関する研究" コンクリ-ト工学年次論文報告集. Vol.12 No.2. 191-196 (1990)

小岛隆之：“PRC构件极限纯扭转强度的研究”《混凝土工程年报》第12卷第2期（1990）。