高强玻纤格栅软基加固传荷机理现场试验研究

Field test study of the mechanism of reinforcing the soft foundation of high strength glass fiber grids

针对高强（每延米纵、横向极限抗拉强度≥300 kN/m）玻纤格栅软基加固荷载传递机理问题,结合季节性＂低温区＂（冬季漫长,最低气温-30℃）某高速铁路DK369＋335.13~DK369＋795.53标段（采取＂CFG桩＋土工格栅＋水泥级配碎石＂软土地基处理方式）300 d现场试验实测数据,研究了高强玻纤格栅软基加固作用下路基的变形、应力变化、桩土应力比和格栅受力特点。结果表明：地基沉降、桩土应力和格栅应变主要发生在填土期,随荷载试件效应累计速率较快;双层高强玻纤格栅因刚度较大,抗力能力强,承担上覆土时具有＂驾驭效应＂,和水泥级配碎石一起协同工作,桩、土之间的应力更加均匀,共同承担上部荷载;恒载期高强玻纤格抵抗冻土及雨、雪产生的附加荷载效应较好,侧面验证了其在季节性低温区高速铁路软基处理中无法比拟的优越性。

Aiming at the load transmission mechanism of high strength（ soft per meter of longitudinal and lateral ultimate tensile strength is greater than or equal to 300 k N / m） glass grids in soft foundation,combined with 300 days of the field tests of a highly railway DK369 ＋ 335. 13 to DK369 ＋ 795. 53 tenders（ ＂ CFG pile＋ geotechnical grille and cement gradation macadam＂ soft soil foundation treatment） in low temperature zone＂（ the long winter,minimum temperature of- 30 ℃）,subgrade deformations,stress,pile-soil stress than grille and stress characteristics under the action of high strength glass fiber geogrids reinforcement of soft soil foundation are examined in this study. The results show that foundation settlement,pile soil stress and grid strain mainly occurred in the filling stage,and the load test effect cumulative rate is quicker; double layer high strength glass fiber grids has the ＂ control effect＂ on the time of the overlying soil because of its high rigidity,strong resistance ability,and the stress of the pile and the soil is more uniformly working with the cement gradation grave and the upper load is shared. The high strength glass fiber grids in the constant load period is better to resist the frozen soil and rain and snow,with the side verification of its advantages in the treatment of soft foundation in seasonal low speed railway soft foundation.