软土在我国分布广泛，它抗剪强度低变形大，如果处理不当，地基会产生局部或整体剪切破坏。乐温高速公路部分路段穿越软土地区，为了保证上部结构安全正常使用，必须对软土路段进行处理。目前处理软土路基的方法有很多种，粉喷桩是其中一种，该法对于工期紧、软土性质较差的地基有着较理想的处理效果。本文以粉喷桩处理乐温高速公路软基为工程背景，对软土路堤边坡的稳定性和软土加固措施进行分析，并通过数值模拟及软土路堤施工过程的监测对粉喷桩加固软土地基的效果进行评价，获得以下几点认识： (1) 利用软土路堤的极限填土高度理论对天然软土路堤的填土极限高度进行计算，同时采用岩土分析软件Geo-slope分析天然软土路堤边坡的稳定性，通过这两种方法得出的结果表明必须对该研究区软土地基进行加固； (2) 采用工程类比法和试桩试验确定了粉喷桩的设计参数，并对软基加固后的沉降量和安全系数进行计算，结果表明软基加固后满足工程要求； (3) 利用有限元对粉喷桩复合地基沉降及孔隙水压力进行了数值模拟，并分析了影响粉喷桩的复合地基沉降的因素； (4) 在施工过程中，对软土路堤的沉降和稳定性进行动态监测，分析软土地基沉降、侧向位移等的变化规律，提出控制填土速率的标准。通过路堤施工的观测结果表明，粉喷桩在乐温高速公路的应用是成功的。

Distributed widely in our country, soft soil has the characteristics of low shearing strength, large deformation. If soft soil was treated in mistake way, foundation would come into being local shear failure or general-shear failure. In Le-Wen highway engineering, the partial road sections cross soft soil. For ensuring the safety of superstructure, it is important to treat soft soil roadbed. The technique of the Dry Jet Mixing Method (DJM) is one of treating technologies of soft soil roadbed presently. The DJM has the ideal reinforcement effect to the bad character of soft soil in a time-limited project. The background of this paper is the using of the DJM in Le-Wen highway soft base, the soft soil slope of embankment stability and soft soil reinforcement measure are analyzed.The reinforcement effect of DJM is appraised through numerical simulation and monitor on construction process of soft soil embankment. Following conclusions are obtained. (1) Using the theory of filling emergency altitude of soft soil embankment, filling emergency altitude of natural soft soil is calculated; the stability of natural soft soil embankment slope is analyzed by using the software Geo-slope. The results of two approaches indicate that soft soil foundation needs for the reinforcement. (2) The design parameters of the DJM are identified by engineering analogism and the test pile, and the settlement quantity and safety coefficient of reinforcement foundation are calculated. The results indicate that the project request is satisfied; (3) The settlement quantity and pore water pressure of the DJM complex foundation are simulated by the finite element method, and the impact factors of composite foundation settlement are analyzed; (4) In the construction process, the embankment stability and settlement of soft soil have been monitored dynamically, and the settlement and lateral displacement of soft soil foundation and etc. have been analyzed, and the control standard of fill speed has been proposed. The observation results have indicated that the application of the DJM in the Le-Wen highway is successful.