Study On A New Technology Of Slurry Pocket Soil Nailing And Working Mechanism

Soil Nailing has been widely used in foundation pit engineering with its advantages such as light construction equipment, simple operation, fast construction, litter material dosage, and low cost. The strength of soft clay is low, the controllability of grouting in conventional soil nailing construction is poor, pull-out resistance of soil nail is weak, construction quality assurance is difficult and other else, what makes soil nailing using greatly limited. In addition, the soil nails are often beyond the end of red line, so it will become an obstruction for future construction of underground pipeline or buildings nearby. If the soil nails can be recycled and reused,materials can also be saved a lot, project cost will be reduced, and good economic benefits will be achieved.Thesis work carried out in the following areas:1. Study the new slurry grouting pocket reaming soil nail technology. With this new technique, the soil nails can receive a better pull-out resistance capacity, better construction quality managment,and it is particularly suitable for use in soft ground.2. Study the new recycling technology to enhance the pullout force and grouting controllability of soil nail, and to attain the purpose of recovery of reinforcement.3. Carry out the on-site pullout testing and study of bearing properties of slurry grouting of soil nails and recycling nails, and proposed two new soil-nail ultimate resistance calculation. Calculated values agree well with the measured values, therefore it is on the safe side for practical application.4. Appling ABAQUS finite element software to establish three finite element analysis models: pull-type soil nail, pressure-type soil nail and tension-compression nail. To study the transfer law of load through with numerical simulation examples, and analyzed the effct of load level, length of grouting, grouting diameter and soil parameters on stress distribution of soil nails.