Adv. Construction Methods & Materials Adv. Construction Methods & Materials (CE 5389) Table Of Contents Problem 1 3-5 Problem 2 5-6 Reference 7 1|Page Adv. Construction Methods & Materials Problem 1: Prepare and submit a table summarizing deep foundation types you think should be used in the given soil conditions and load requirements listed below. Use your judgment and guess a little but think it through based on logic. You may want to peruse parts of the internet if you need a little more understanding of soil information. A deep foundation is a type of foundation used in construction to transfer structural loads from a structure to a deeper and more stable layer of soil or rock below the ground surface. Deep foundations are used when the upper layers of soil or surface conditions are inadequate to support the structure directly. They are typically used in the following situations: Weak or Unstable Surface Soils, High Structural Loads, Expansive Clay Soils, Nearby Excavations, etc. Types of deep foundations include: Piles: Driven or drilled into the ground to reach the bearing stratum. Piles can be made of steel, concrete, timber, or other materials. Drilled Shafts (Caissons): Large-diameter holes drilled into the ground and filled with concrete or reinforced concrete. They provide both axial and lateral load-bearing capacity. Pier Foundations: Used for bridges and elevated structures, pier foundations consist of multiple columns or piers that transfer loads to deep footings. Sheet Pile Walls: Used as retaining walls or for waterfront structures, sheet piles are interlocking vertical steel sheets driven into the ground. The choice of deep foundation depends on the specific soil conditions, structural requirements, site constraints, and cost considerations. 2|Page Adv. Construction Methods & Materials SUGGESTED DEEP FOUNDATION Pile Design Load 1 20 Tons Deep Foundation Type: Ground Conditions 10 feet of soft peat over 80 feet of dense sand Driven piles (drilled shafts): typically made of concrete, steel, or timbers. Here the dense sand provides a stable bearing layer at this significant depth. The piles need to extend through the soft peat layer into the dense layer to ensure proper load bearing. Drilled shafts (Caissons): this method allows for better control over the depth and alignment of the elements of foundation. In this case the engineers can design the shafts to penetrate through the soft layer until it reaches the stable layer and load bearing can be achieved by interaction between the shaft and the surrounding soil. 2 50 Tons 10 feet of soft peat over 80 feet of dense sand Drilled shafts (Caissons): they can be designed to carry heavy loads. Since they can provide a large diameter and depth. reinforced with steel or concrete. These types provide control over alignment and depth which is important here while transitioning from soft layer to dense sand. 3 50 Tons 60 feet of soft clay over hard limestone Deep Foundation Type: End-bearing-pile: these types are typically long and slender and are installed vertically through the less stable layer until they reach the bearing layer. commonly used in construction projects where the upper soil layers are soft, compressible, or unsuitable for bearing structural loads. They are often employed in areas with deep or variable soil profiles. They are also costeffective options for this scenario. 4 50 Tons 80 feet of loose sand over hard shale Deep Foundation Type: Driven piles: these types of piles have load bearing capacity for this scenario and can easily transition through loose sand and will compact the sand around it which can help to provide more stability and after it entered to the hard layer of the soil, they will achieve a great load bearing capacity. They are usually cost effective. Precast concrete piles: they could carry large amounts of load and have a proper length for this scenario with about 50 ft or more by engineering design. 3|Page Adv. Construction Methods & Materials 5 100 Tons 80 feet of loose sand over hard shale Deep Foundation Type: Drilled shafts (Caissons): they can be designed to carry heavy loads as 100 tons here. They penetrate through loose sand and during drilling the loose soil can be excavated and replaced with concrete providing more stability. Until they reach the hard shale then they have a very good capability for carrying the load they also reduce the risk of settlement and can resist lateral loads. 6 2000 Tons 150 feet of soft clay over hard shale Deep Foundation Type: Drilled shafts (Caissons): These shafts are typically reinforced with concrete to provide better load bearing capacity. On this scenario a combination of drilled shafts and ground improvement techniques to improve soft soil layer and reduce the settlements is best approach. When the shafts penetrate through the loose layer until they reach the more stable layer of the soil to sit on it. Problem 2: Provide a list of factors that can affect the amount of energy applied to driving a pile and how each of these factors can affect the process. Pile driving is a complex process influenced by various factors, including soil conditions, equipment, and design considerations. Properly assessing and managing these factors is essential to ensure efficient and effective pile installation in construction and engineering projects. Soil Conditions: Impact: Soil type, density, and consistency play a crucial role. Dense soils require more energy than loose or softer soils. Operator Skill and Experience: Impact: The skill and experience of the equipment operator can affect the efficiency of the pile driving process, optimizing energy application. Environmental Conditions: Impact: Factors like temperature, humidity, and wind can affect the efficiency of pile driving equipment and the behavior of the soil. Equipment Maintenance: Impact: The condition and maintenance of the pile driving equipment, including the hammer and leads, can impact its efficiency and energy transfer. 4|Page Adv. Construction Methods & Materials Hammer Efficiency: Impact: The efficiency and weight of the hammer used for driving affect how much energy is transferred to the pile. Heavier, more efficient hammers may require less energy. Hammer Type: Impact: Different types of hammers (e.g., drop hammers, diesel hammers, hydraulic hammers) have varying energy transfer mechanisms, impacting energy application. Pile Type & Material: Impact: Different pile materials such as steel, concrete or timber and shapes have varying resistance to being driven into the ground, affecting the energy needed. Monitoring and Adjustments: Impact: Real-time monitoring allows for adjustments in driving parameters to optimize energy application if the pile isn't progressing as expected. Pile Length: Impact: Longer piles require more energy due to increased resistance as they penetrate deeper into the ground. Human error: Impact: workmanship can also be a factor since machines need to be operated by humans, and human errors are inevitable. 5|Page Adv. Construction Methods & Materials References: Learning material and videos provided by Professor Marshall. https://acculevel.com/types-of-soil-and-the-effects-on-foundations/ https://www.ramjack.com/about/news-events/2015/august/different-soils-how-they-affectfoundations/ https://www.foundationrecoverysystems.com/glossary/types-of-soils/ https://vulcanhammerinfo.files.wordpress.com/2017/08/efficiency.pdf 6|Page
