目前竹类研究主要以毛竹等大径级竹材为研究对象，方竹及小径级竹材的研究与应用较少。以竹材物理力学性能试验方法为依据，对3~5年生的111个昭通方竹片状试样进行了力学试验，测定了拉压强度、弹性模量等参数。基于试验数据，确定了强度概率分布并验证了其分布特性。结合木结构研究成果与可靠度极限状态设计法，得出了方竹的强度标准值和设计值，并通过与毛竹、落叶松等材料的对比，验证了其可行性。针对不满足规范要求的顺纹抗压强度设计值，进行了可靠度指标修正。本研究丰富了小径级竹材的力学性能数据库，也为方竹的进一步研究与应用开拓了新的方向。

At present, the research on bamboo mainly focuses on large-diameter bamboos such as moso bamboo, and the research and application of square bamboo and small-diameter bamboos are rare. Based on the test method of physical and mechanical properties of bamboo, the mechanical tests were carried out on 111 Zhaotong square bamboo flake samples born in 3~5 years, and the tensile and compressive strength, elastic modulus and other parameters were determined. Based on the experimental data, the intensity probability distribution was determined and its distribution characteristics were verified. Combined with the research results of timber structure and the reliability limit state design method, the strength standard value and design value of square bamboo were obtained, and its feasibility was verified by comparison with moso bamboo, larch and other materials. The reliability index was corrected for the design value of the compressive strength of the grain that did not meet the requirements of the code. The result enriches the database of mechanical properties of small-diameter bamboo, and also opens up a new direction for the further research and application of bamboo.