110年 - 110 國立中央大學_碩士班招生考試_土木工程學系/大地工程組(一般生):土壤力學及基礎工程#105334

a) Please write down the full English titles for CPT and SPT (2%)

b) Which one can be used for retrieving soil samples during testing? (2%)

c)Which one can be used for detecting thin soil layers underground? (2%)

2) In-situ stress (4%) As shown below, a 9-m-thick layer of saturated clay is underlain by a layer of sand. Calculate the maximum depth of cut H that can be made in the clay layer?

a) the clay is normally consolidated (5%)

b) preconsolidation pressure = 200 kN/m² (5%)

c) preconsolidation pressure = 150 kN/m² (5%)
Note that Cc = 0.178 and C_s = 0.2Cc

4) Soil strength (10%)
The result of two CD triaixial tests is as follows:σ₃= 70 kPa, deviator stress at failure = 130 kPa;σ₃ = 160 kPa, deviator stress at failure = 223.5 kPa; please find c andΦ

5) (3%) What is the English full title of USCS?

6) (2%) What is the definition for soil water content?

7) (10%) For a moist soil sample, given V = 1.2 m³, M = 2350 kg, water content w = 0.086, Gs = 2.71, please find:

1. Moist density
2. Dry density
3. Void ratio
4. Porosity
5. Degree of saturation

8) 25% 某臨海工業區之水力回填砂質地盤,地盤之剖面分佈與參數如下圖所示。現設一椿徑為1m,長度為30m之打擊式基樁,試以β法估計其樁周摩擦承載力,(假設樁周摩擦強度之臨界深度為=15D)。以樁底承載力公式