Desiign And Construction Of Pavements Over Weak Soils

Date : Sep 2016 - Jun 2017

In this project, engineering properties of weak soils were studied especially their response to pavement loading was highlighted. The effect of various techniques of stabilization (surface compaction, vibration method, use of geotextiles and fabrics etc.) has been studied on weak subgrades. The effect of various additives on soil strength is discussed, especially the effect of lime is highlighted. Based on liquid limit, plasticity index of soil sample, availability and economic considerations, lime was selected as stabilizer. Then CBR test was performed on weak soil sample as well as weak soil mixed with lime. Different values of CBR against various concentration of lime was found. Considering the economic and strength requirements specific percentage of lime was selected for further design procedure. Based on CBR test results, flexible and rigid pavements were designed for weak as well as stabilized subgrade. Procedure for the construction of flexible and rigid pavements has also been discussed. Diverse types of defects that may occur after construction are mentioned along with their remedial measures. Increase in California Bearing Ratio with the addition of lime suggests that lime can be used effectively to enhance the properties of weak subgrades. Thus, it is suggested that use of lime as stabilizer is an effective and economical option for the weak soils. From results, it is suggested that construction of pavement over poor subgrade is uneconomical and reliability level is low so the construction of pavement over stabilized soil is effective option.