HW$-1$

Find the required thickness $(t)$ of a HDPE geomembrane beneath a $30m$ high landfill containing municipal solid waste with a unit weight of $12k\frac{N}{m^3}().$ The localized subsoil settlement is estimated to result in a liner deformation angle of $20().$ Drainage sand is above the geomembrane and a geonet is below it$.$ Given: ${}_{\text{a}\text{l}\text{l}\text{o}\text{w}}=20,000$kPa,${}_u=18$

${}_L=10,x=70mm.$