But on the top of the foundation sandwich or weak soil varying from thin to thick often exists, this has direct influence on the efficiency and expansion of this method.

• 振动挤密砂石桩复合地基的应用已取得较好效果,但其上部常存在软弱土层或夹层、厚薄不一,直接影响了该方法的推广和效应。