Merit Engineering has provided complete geotechnical engineering services from subsurface investigation through construction phase earthwork observation. Test borings were conducted, soil and groundwater conditions logged, and representative soil samples collected. Merit Engineering then conducted laboratory tests including sieve analysis, Atterberg limits, moisture content and unit weight measurement, and consolidation test. Merit Engineering completed engineering analysis including consolidation and elastic settlement of foundation. Merit Engineering also provided complete earthwork observation, inspection, and technical support during construction. The prompt response and competent analysis and recommendations Merit Engineering provided during earthwork phase ensured the project on schedule and success.
The significance of geotechnical engineering in this project is the achievement of using conventional shallow spread footing for this heavy building instead of much more expensive pile foundation. The soils at this site are mainly glacialmarine drift clayey soil underlain by coarse gravel and sand. The 50?? thick layer of clay was over-consolidated at both ends while the middle 10-ft of clay was soft and highly compressible. With our rigorous engineering analysis based on reliable field testing and laboratory test program, we derived the foundation plan which controls projected settlement to acceptable limit.
Another important achievement in geotechnical engineering excellence in this project is the design for open cut slope without shoring support during construction. This design contributed to significant savings for the project. We have observed that sheet pile shorings were employed for excavations on nearby sites with similar soil conditions, and with much less critical structures at much farther distances from excavations, and those excavations were carried out during summertime dry season. The cut in this project was about 15′ high near an existing building (about 10′ away). The earthwork proceeded during wet weather. Merit Engineering recommended for a safe cut slope without need of support based on field test borings and laboratory test results as well as field examination on the soil and groundwater conditions during excavation. The excavation was completed with the recommended cut slope and left open safely for four months in the wet wintertime from November through February.
Merit also conducted a geotechnical investigation for a proposed 700-car parking lot and associated sewer and storm drains. We analyzed soil and groundwater conditions based on the results from test pits, provided recommendations for pavement structure design, and provided construction phase support and soil testing services.