减小真空预压区外土体侧向变形的措施

Measures for reducing lateral deformation of soil outside vacuum preloading area

结合某真空预压加固软基工程中出现的临近建筑物拉裂问题,进行了真空预压对周围土体变形影响及减小其影响的防护措施的现场试验研究.研究结果表明,真空预压影响区范围与周围土体的土质条件有关,超软土地基的影响距离超过50 m,而加固区外土层条件较好时的影响距离很小,在真空预压区外采取打设高压旋喷桩、水泥搅拌桩防护墙等技术措施可以减小上部土层的侧向变形.

The study was performed to investigate tension cracking of buildings close to the vacuum preloading area in a soft ground improvement project. Field tests were carried out to study the influences of vacuum preloading on the deformation of surrounding soil and the protective measures for its reduction. It is found that the influence range of vacuum preloading is related to soil characteristics, the influence distance being more than 50m for super-soft soil ground, and it being small for good ground condition, and that the lateral deformation can be reduced by some technical measures, such as arrangement of high-pressure jet grouting pile-reinforced protective walls and cement-slurry mixing pile-reinforced protective walls along the side of vacuum preloading area.