刚性桩复合地基在岩溶地区水泥库地基处理中的应用

刚性桩复合地基是靠桩端阻力和摩阻力共同作用,以摩阻力为主属于磨擦桩,上部载荷由桩和被改良的天然地基土体共同承担。通过工程实例说明在岩溶地区大载荷作用下利用刚性桩复合地基代替桩基既安全可靠又经济,值得推广应用。     

褥垫层对单桩复合地基桩侧摩阻力影响的有限元分析

运用ABAQUS有限元分析软件,分析了在一定地面堆载作用下,褥垫层厚度和变形模量的改变与单桩复合地基桩侧正、负摩阻力大小以及中性点位置的变化关系。结果表明,荷载和褥垫层模量一定时,褥垫层厚度增加对桩充分发挥正摩阻力有利,中性点位置上升;褥垫层厚度小于0.5m时,增加褥垫层变形模量,桩侧正摩阻力也随之提高,中性点位置提升;褥垫层厚度大于0.5m时,增加褥垫层变形模量,其提高更明显。利用数值模拟分析褥垫层对单桩复合地基的桩侧摩阻力影响,可为研究复合地基荷载分担、荷载传递以及工作性状提供借鉴。     

纸浆模塑的缓冲特性

本文绘制了纸浆模塑材料的缓冲曲线图,并与聚苯乙烯泡沫塑料(EPS)的曲线图进行了比较。纸浆模塑材料的某些缓冲特性是由于将其模塑成多个“窝状”波纹纸浆板所形成的。当纸浆模塑材料发生撞击时,这些“窝状”波纹发生相互碰撞而减缓了冲击。研究结果表明,纸浆模塑试样对于低静载、低跌落高度及一次性冲击具有良好的缓冲特性。但是,这种材料的缓冲特性在5kPa(千帕)以上的静载时。以及大跌落高度或多次性冲击条件下就比EPS的差。通过两个试样的“窝状”波纹相互叠合后,这些特性就能得到改善。可以得出这样结论,这种材料在某些情况下具有代替EPS的潜力,本文还为将来的研究工作提出了某些建议。     

Cushioning properties of moulded pulp

Cushion curves for a moulded pulp material were constructed and compared with cushion curves for an expanded polystyrene (EPS) foam. The ability of the moulded pulp material to provide some shock absorption resulted from a number of ‘dimples’ moulded into the pulp sheet. As an impact was applied to the moulded pulp, these dimples crushed and thereby mitigated the shock. Results showed that the moulded-pulp test samples had good cushioning characteristics for low static loadings, low drop heights, and single impacts. However, the cushioning characteristics of the material were inferior to those of EPS foam at static loadings above about 5kPa, and where higher drop heights or multiple impacts occurred. These properties were improved by using two samples with interlocking dimples. It was concluded that the material had the potential to replace EPS foam in a limited number of situations, and several recommendations for future research were given.