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1 前言在土石坝及堤防工程中,基础与地基的联接及防渗大多是刚性砼结构,如砼防渗墙,龄墙等。一般结构尺寸往往较大,强度和刚度相对周围土体而言较大,结构设计时,为防止土体施于墙预应力过大和地基基础不均匀沉陷造成墙体断裂破坏,因而材料用量和造价较高,大江大河的堤坝基础与地基用塑性砼“软”结合。这不仅改善了墙体与地基及周围土体的变形适应性问题,同时也达到了防渗加固的目的。低弹塑性砼较之常态砼在材料方面表现为水泥用量少,在性能上表现为抗压强度低,切线弹模小,极限变形量较大,凝结时间较长,防渗性能好等特点。据有关文献介绍,低弹塑性砼墙体与周围冲积层地基土体的相对变形或沉降只有几个 mm 之差,既与地基基础的变形基本接近,从而使结构在地基及基础中的稳定性增强。
1 Introduction In earth-rock dams and dike projects, the foundation and foundation joints and seepage control are mostly rigid concrete structures, such as concrete cutoff walls, age walls and so on. General structure size is often larger, strength and stiffness relative to the surrounding soil in terms of larger, structural design, in order to prevent the soil applied to the wall prestressed too large and uneven subsidence of the foundation wall rupture caused by damage to the wall, so the amount of material and cost Higher, large river dam foundation and foundation with plastic concrete “soft ” combination. This not only improves the deformation adaptability of the wall and foundation and the surrounding soil, but also achieves the purpose of seepage prevention and reinforcement. Compared with the normal concrete, the low elastic-plastic concrete shows less amount of cement in terms of materials, which is characterized by low compressive strength, small tangent elastic modulus, large deformation limit, long setting time and good impermeability. . According to relevant literature, the relative deformation or settlement of the low elastic-plastic concrete wall and surrounding alluvial soil is only a few mm difference, which is basically close to the deformation of foundation, so that the stability of the structure in foundation and foundation Enhanced.