本文旨在探討鋼筋混凝土梁剪力容量設計之安全性。2002年陳和呂針對根據ACI318-99規範進行剪力容量設計之梁，探討其安全性。本文針對根據 ACI318-02規範進行剪力容量設計之梁，在考慮混凝土強度、鋼筋強度，斷面 尺寸，混凝土極限壓縮應變及載重等皆為隨機變數之情形下以蒙地卡羅法分析其破壞機率。研究結果顯示，若剪力破壞機率限制為4%'則對於撓曲鋼筋採用SD280之梁並不保守，對於撓曲鋼筋採用SD420之梁卻又稍嫌過於保守。就剪力破壞機率而言，根據ACI318-02規範進行剪力容量設計之梁，其剪力 破壞機率會低於根據ACI318-99規範進行剪力容量設計之梁。

The objective of this paper is to investigate the safety of the shear capacity design of reinforced concrete beams. The safety of the shear capacity design of beams designed using the ACI 318-99 Code was investigated by Chen and Lu (2002). The random variables considered in this study are the concrete strength， the reinforcing steel strength， the cross section dimensions， the ultimate compression strain on the concrete and the loading. Theprobability of shear failure of beams designed using the ACI 318-02 Code is determined by the Monte Carlo technique. Ifthe probability of shear failure is limited to 4%， beams with SD 280 flexural steel are not conservative， but beams with SD 420 flexural steel are over ωnservative. The probability of shear failure of beams designed using the ACI 318-02 Code is however; lower than when using the ACI 318-99 Code.