Geotechnical and Foundation Engineering Review Flashcards

Fill-in-the-blank flashcards covering soil origin and properties, history of soil mechanics, structural foundation design criteria (NSCP 2015), and soil bearing capacity theories.

Soil is defined as the uncemented aggregate of mineral grains and decayed organic matter with liquid and gas in the empty spaces between the __________ particles.

solid

Geotechnical engineering is the subdiscipline of civil engineering that involves natural materials found close to the surface of the earth, including the application of __________ mechanics and rock mechanics.

soil

In the Bowen classification, the __________ ferromagnesian reaction series forms minerals that are different in their chemical composition and crystalline structure.

discontinuous

Soils formed by weathered products at their place of origin are called __________ soils.

residual

Soils formed by transportation and deposition in quiet lakes are categorized as __________ soils.

lacustrine

Soils formed by the movement of soil from its original place by gravity, such as during landslides, are called __________ soils.

colluvial

Deposits of gravel, sand, silt, and clay formed by weathering that become compacted and cemented by agents like iron oxide form __________ sedimentary rocks, which all have a clastic texture.

detrital

According to the Unified Soil Classification System (USCS), soil particles are classified as silt or clay if their size is less than __________ $mm$.

$$0.075$$

In mechanical analysis of soil, __________ analysis is used for particle sizes smaller than $0.075\,mm$ in diameter based on sedimentation in water.

Hydrometer

The uniformity coefficient ($C_u$) is defined mathematically as the ratio of $D_{60}$ to __________.

$$D_{10}$$

Flaky soil particles, which are predominantly clay minerals, have a very low sphericity usually equal to or less than __________.

$$0.01$$

Dikes dating back to about 2000 BC were built in the basin of the Indus to protect the town of __________ in present-day Pakistan.

Mohenjo Dara

According to Skempton (1985), the period of soil mechanics spanning from 1700 to 1776 AD is designated as the __________ period.

Pre-Classical

In 1717, French royal engineer Henri Gautier studied the natural slopes of soils when tipped in a heap, which is now referred to as the angle of __________.

repose

French scientist __________ used the principles of calculus for maxima and minima in 1776 to determine the true position of the sliding surface in soil behind a retaining wall.

Charles Augustin Coulomb

In 1856, French engineer Henri Philibert Gaspard Darcy published a study on the permeability of __________ filters.

sand

Swedish chemist and soil scientist Albert Mauritz Atterberg defined the clay-size fraction as the percentage by weight of particles smaller than __________ microns in size.

$$2$$

The Austrian engineer known as the father of modern soil mechanics is __________.

Karl Terzaghi

A __________ foundation is defined as one where the width of the foundation is greater than its depth.

Shallow

A __________ or strap footing consists of two footings joined by a beam instead of a bearing portion of the footing.

Cantilever

According to NSCP 2015 Table 304-1, Intact Tuffaceous Sandstone has an allowable foundation pressure of __________ $kPa$.

$$1,000$$

For a foundation supporting 3 floors, NSCP 2015 Table 305.1 requires a minimum footing width of __________ $mm$.

$$450$$

The unit weight of concrete used in calculating effective soil bearing capacity ($q_e$) is usually taken as __________ $kN\,m^{-3}$.

$$23.5$$

In rectangular two-way footings, the factor $\gamma_s$ representing the portion of short-direction reinforcement in the center band width is calculated using $\gamma_s = \frac{2}{\beta + 1}$, where $\beta$ is the ratio of the long side to the __________ side of the footing.

short

The minimum flexural reinforcement area ($A_{s\min}$) in footings is the greater of $\frac{0.25\sqrt{f'_c}}{f_y} b_w d$ and __________ $\frac{b_w d}{f_y}$.

$$1.4$$

The maximum spacing $s$ of deformed reinforcement in footings shall be the lesser of $3h$ and __________ $mm$.

$$450$$

For deformed bars with $f_y < 420\,MPa$, the minimum ratio of shrinkage and temperature reinforcement area to gross concrete area is __________.

$$0.0020 A_g$$

In one-way shear strength calculations for footings, the strength reduction factor $\phi$ for shear is equal to __________.

$$0.75$$

In two-way shear calculations for footings, the coefficient $\alpha_s$ is equal to __________ for interior columns.

$$40$$

Dowels providing connections between cast-in-place members and foundations shall not be larger than __________ $mm$ in diameter.

$$36$$

For $f_y \le 420\,MPa$, the compression lap splice length $L_{sc}$ of bars $36\,mm$ diameter or smaller is the greater of $0.071 f_y d_b$ and __________ $mm$.

$$300$$

According to Terzaghi, shallow foundations are those placed at a depth $D_f$ not exceeding the __________ of the foundation.

width

The maximum pressure that the soil can support above its current overburden pressure is called the ultimate __________ bearing capacity.

net

In geotechnical engineering, a factor of safety between 1.5 and __________ is used to calculate allowable bearing capacity.

$$5$$

__________ shear failure occurs in soils with brittle stress-strain behavior, causing sudden foundation tilting and ground bulging.

General

Soil failure characterized by significant penetration of the foundation without visible ground bulging and where shear planes are not properly defined is called __________ shear failure.

punching

In Terzaghi's ultimate bearing capacity formula for a strip footing under general shear failure, $q_u = c' N_c + q N_q + 0.5 \gamma B N_\gamma$, the constant factor multiplying the unit weight term is __________.

$$0.5$$

For a square footing under general shear failure, Terzaghi's bearing capacity formula gives a cohesion term coefficient of __________.

$$1.3$$

When evaluating local shear failure using Terzaghi's equations, the modified cohesion $\bar{c}'$ is taken as __________ times the original cohesion $c'$.

$$\frac{2}{3}$$

When the groundwater table is located at a depth $d_w$ below the base of the footing where $d_w < B$, the modified unit weight $\gamma_c$ is calculated using the approximate equation $\gamma_c = \gamma_b \left(1 + \frac{d_w}{B}\right)$, where $\gamma_b$ is the __________ unit weight.

submerged