Clark Foundations' scope included designing and installing the SOE for the 25-story tower and parking garage. The parking garage excavation is 55 feet deep and totals 20,740 square feet. The SOE system comprised 105 drilled soldier piles, extensive wood lagging, and internal bracing, tailored to the site's unique challenges. The SOE consisted of 105 drilled soldier piles, 34,050 square feet of wood lagging, 150 50-foot-long external tiebacks, and 450 tons of internal bracing. 

Project Coordination
The Hampden House project faced complex site conditions, necessitating close coordination among Clark Foundations, the client, the base construction team, WMATA, and Montgomery County. The project's proximity to the ongoing Purple Line construction and an existing WMATA tunnel added layers of complexity. Coordination started early during design development, ensuring all parties met design requirements and incorporated feedback on support-of-excavation (SOE) designs. Regular construction meetings helped address challenges, such as the impact of Purple Line construction on the Hampden House SOE. When Purple Line contractors wanted to install a gantry crane to remove rock from the 100-foot shaft, the crane's footings could affect the Hampden House SOE already in place. Clark Foundations worked with the contractors to connect the Hampden House system to existing piles, adding wales and struts for extra support during the excavation. Collaborative solutions involved connecting systems and reinforcing support, demonstrating adaptability and proactive problem-solving.

Quality of Workmanship
Given the tight site conditions at Hampden House, precision in installing the SOE system for the 25-story tower and parking garage was paramount. In addition to the proximity to the Purple Line and a WMATA tunnel, the unexpected discovery of quartz and previous SOE structures complicated the design. The project team maintained high standards by meticulously measuring and marking installation points, minimizing waste and rework, and bringing additional equipment on site to drill through the rock. This precision ensured the project remained on schedule and provided educational opportunities for junior team members. 

Excellence in Construction
The Purple Line shaft, located 10 feet from the site, prevented the use of external bracing and necessitated creative internal bracing solutions for the narrow, deep site. The team designed a solution with 30 steel struts, each 95 feet long. These were delivered in 45-foot sections, welded on site, and lifted by crane. The design had to account for deflection precisely due to the lack of middle supports. During construction, the tower crane's footing changed. The team used tiebacks on the north and east sides, removing corner braces, as rakers weren't an option on the north side's last tier. On the east side, they replaced corner braces with rakers, which required coordination with the footings.