Interaction between Engineered Cementitious Composites Lining and Foundation Subsurface Drain

Abstract

The effect of cyclic loads on the surface profiles of ECC linings cast on foundations comprising crushed stone and compacted soil was investigated. A geotextile was embedded between the crushed stone and ECC lining for some of the samples. After 28 days of water curing, the hardened surfaces were loaded and monitored for roughness and crack development by measuring surface levels and crack widths, respectively. Neither cracking nor significant variations in the lateral profiles were observed on all the samples for all the loads applied. However, significant variations which depended on the foundation types were observed in the vertical profiles. It was concluded that while ECC can resist cracking due to its high strain capacity, its flexibility causes ECC linings to assume the shape of the foundation material, which can increase the surface roughness at certain loading configurations.

Numerical Analysis of the Response of Pile-Raft Systems Considering the Application of Cement and Polypropylene Fiber Treatment

“…In order to model soil behavior, experimental results obtained by Tang et al [18] for the soil of Nanjing area, China were applied. Table (1) presents physical and mechanical properties of soil. Ordinary Portland cement with compressive strength (28-day) of 33.4 MPa and specific surface of 387 m 2 /kg was used for stabilization of this soil.…”

“…As observed in Fig. (1), in order to study the effect of width and depth of stabilized soil on the performance of foundation, soil under foundation was divided into vertical and horizontal blocks. This division has been axisymmetric in such a way that the letters show the block width and the numbers indicate the block depth.…”

“…For instance, the block of B3 in Fig. (1) shows stabilized soil with the width of 10 and depth of 3 m.…”

“…By growing population and lack of appropriate soils, many civil engineering projects have to be constructed on weak soils, which have a great potential of failure due to low strength and high compressibility of underlying soil. Therefore, various improvement methods such as physical stabilization [1,2], chemical stabilization [3][4][5][6], reinforcement with fibers [7,8] and geotextile [9,10] are utilized. Polypropylene fibers are cheap and strong against different environmental conditions and also can be pre-opened easily.…”

Displacement Monitoring during the Excavation and Support of Deep Foundation Pit in Complex Environment

“…e excavation of the foundation pit is accompanied by the stress redistribution of the surrounding soil [1][2][3][4]. Under the action of earth pressure, a certain displacement will be generated towards the pit, which will affect the stability of the foundation pit and surrounding buildings.…”