黏性土环境中矩形顶管施工的室内试验研究

Study on laboratory tests on construction of rectangular pipe jacking in cohesive soil environment

顶管施工过程中会引起地表土体变形。通过室内试验研究了黏性土环境中矩形顶管施工对地表土体产生的影响。在是否注浆以及顶进管道附近是否有既顶管道的条件下,通过测试系统获得试验过程中的顶力和土体竖向变形变化情况。试验结果表明:顶管顶进过程中,初始顶力均比较大,随后均迅速减小,最终趋向一个稳定值;表层土体变形以沉降为主;新顶进顶管对既有顶管管道上方土体产生影响,但影响有限;既有顶管的存在能减小所需要的顶力,也能减小顶进管道上方的土体沉降;注浆可以有效减小顶管顶进阻力,也能减小土体的沉降。试验结果可以有效指导矩形顶管的施工。

It will cause the surface soil mass deformation during pipe jacking construction. The laboratory tests were carried out to study the impact of rectangular pipe jacking construction in cohesive soil environment on the surface soil. In the condition of whether having grouting method or having existing pipe jacking around the pipe jacking,the jacking force and the variation of the soil mass vertical de-formation can be obtained by system testing. The results show that： during pipe jacking pro ces s , initial jacking force relatively la rg e , then decrease rapidly and eventually tend to be a stable value ; surface soil mass deformation has been dominated by subsidence ; new pipe jacking has impact on the above soil mass of the existing pipe jacking, but the impact is limited ; existing jacking pipe can reduce the jacking force, and soil settlement at the top of the jacking pipe ; grouting method can effectively reduce the jacking re sistan ce, and can reduce the soil mass settlement, too. The test results can effectively guide the construction of rectangular pipe jacking.