# Macroscale Static Mechanical Behaviors of Cemented Sand Gravel Dams with Consideration of Construction Interfaces

## TL;DR

This paper studies how construction interfaces affect the mechanical behavior and safety of cemented sand gravel dams.

## Contribution

The study introduces a method to evaluate construction interface treatments using direct shear tests and finite element modeling.

## Key findings

- Considering construction interfaces increases displacements and stresses in CSG dams.
- Both laying mortar and roughening treatments meet anti-sliding stability requirements.
- Laying mortar provides greater load-bearing capacity compared to roughening.

## Abstract

In order to study the influence of construction interfaces on the safety of middle-low and 100-m cemented sand gravel (CSG) dams, direct shear tests of the construction interfaces with laying mortar and roughening under four different normal pressures are firstly conducted; shear stress–shear displacement curves and interface parameters for the interface models are obtained. Then, finite element models are established using a modified Duncan–Chang constitutive model and a zero-thickness interface model. Displacements, stresses, and anti-sliding stability coefficients of the construction interfaces are obtained, load-bearing capacity is analyzed using the water bulk density overload method, and the obtained results are compared with those of the model without consideration of the construction interfaces. The results show that the obtained displacements and stresses become larger or remain constant when the construction interfaces are considered. The two interface treatment methods (laying mortar and roughening) meet the requirements of anti-sliding stability, and the load-bearing capacity of the construction interface with laying mortar is greater. This study reveals the influence of construction interfaces on the overall mechanical behaviors of the CSG dams and provides technical guidelines for the two construction interface treatments.