Reduction of lateral loads in abutments using ground anchors

In bridge design, economically addressing large, lateral earth pressures on bridge abutments is a major challenge. Traditional approaches employ enlargement of the abutment components to resist these pressures. This approach results in higher construction costs. As an alternative, a formal approach using ground anchors to resist lateral soil pressure on bridge abutments is proposed herein. The ground anchors are designed to minimise lateral forces at the pile cap base. Design examples for high stem abutments (heights 6-8 m) are conducted for a simple 33 m long concrete bridge span, with two to three traffic lanes. The abutments are supported by driven, reinforced concrete piles. As lateral forces at the pile cap are significantly reduced, only one row of piles is needed. When compared with common abutment design, the proposed approach halved the number of piles required and decreased the required abutment volume by 37%.