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地工格网（以下称格网）用於加劲土壤时，除考虑无围压下的张力行为之外，围压下之力学性质更是设计考量的重点。实际工程应用而言，基於经济考虑，期以现地土壤作为回填材料。本研究分别以拉出、围压抗张与直剪三种试验来探讨格网放土壤中之力学行为；并利用凝聚性泥岩与非凝聚性细砂作为回填材料，评估两种回填材料对加劲成效之影响。结果显示，柔性格网之肋条在拉出过程中易扭曲，造成主应力面旋转的现象，以致拉出阻抗大放硬性格网；围压下格网抗张的应力-应变行为可分为三阶段，即束制阻抗期、张力发展期与破坏期。束制阻抗期大都於3％应变内即已完成；在低围压情况拉出阻抗达20％～60％之拉出强度（相同应变），在高围压下达150％。由直接剪力试验结果可以预测：（a）格网／泥岩加劲结构-低围压时，剪力破坏面应通过格网／泥岩之界面；而高围压时，剪力破坏面应通过泥岩上体。（b）格网／细砂加劲结构-低围压与高围压下剪力破坏面应通过格网／细砂之界面。
When Geogrid (hereinafter referred to as grid) is used to stiffen the soil, in addition to considering tension behavior without confining pressure, the mechanical properties under confining pressure are the focus of design considerations. For practical engineering applications, based on economic considerations, the existing soil is used as backfill material. In this study, tensile, confining pressure tensile and direct shear tests were used to investigate the mechanical behavior of the grids in the soil, and the use of cohesive mudstone and non-agglomerating fine sand as backfill materials to evaluate the two backfill materials to reinforce the Effect of the effect. The results show that the ribs of the flexible grid tend to be distorted during the pull-out process, resulting in the rotation of the main stress surface, so as to pull out the impedance and put the hard-character net; the stress-strain behavior of the grid under tensile pressure can be divided into three The stage is the beam impedance period, tension development period, and destruction period. The impedance period of the beam is mostly within 3% of the strain, which is already completed; at the low confining pressure, the pull-out strength (same strain) of 20% to 60% is pulled out and reaches 150% under the high confining pressure. From the results of direct shear test, it can be predicted that: (a) When the grid/mud stiffened structure - low confining pressure, the shear failure surface should pass through the grid/mudstone interface; while the high confining pressure, the shear failure surface should pass through the mudstone Upper body. (b) Grid/fine sand stiffening structures - Shear failure surfaces at low confining pressure and high confining pressure should pass through the grid/fine sand interface.