Mouse ears or curtains on brickwork jointing. These are the small projections which occur when the horizontal and vertical joints intersect A good bricklayer is constantly observant, looking for flaws in the bricks he or she is laying and discarding materials that may affect the quality of finish. Brickwork can be knocked and nudged by other workers nearby, so check the work frequently to maintain plumb and level. Be critical of your own work and aim to constantly improve your own standards, and employers and customers will always be happy to give you work. As previously mentioned, one-brick walling is brickwork built to produce walling with a width of 215mm the length of one brick. This means that bricks can be laid across the wall as well as in line with the wall. The bricks laid across the wall are called headers, and the bricks in line with the wall are called stretchers, because of the relevant faces of the brick showing in the finished wall. The half-round joint is also commonly referred to as a bucket handle joint. This is because the shaped handle found on old metal buckets was used to form joints in the past.

Typical values for total unit weight (t) are 110 to 130 pcf (17 to 20 kN/m3). Besides the total unit weight, other types of unit weight are used in geotechnical engineering. For example, the dry unit weight (d ) refers to only the dry soil per volume, while the saturated unit weight (sat) refers to a special case where all the soil voids are filled with water (i.e., saturated soil). Another commonly used unit weight is the buoyant unit weight (b) which is used for calculations involving soil located below the groundwater table. Table 6.6 presents various equations used to calculate the different types of unit weights. Note in Table 6.6 that w  water content and G  specific gravity of soil solids. The void ratio (e) and degree of saturation (S) are discussed in the next article. 6.3.4 Phase Relationships Phase relationships are the basic soil relationships used in geotechnical engineering. They are also known as weight-volume relationships. Different types of phase relationships are discussed below: Void Ratio (e) and Porosity (n). The void ratio (e) is defined as the volume of voids (Vv) divided by the volume of solids (Vs). The porosity (n) is defined as volume of voids (Vv) divided by the total volume (V). As indicated in Fig. 6.7, the volume of voids is defined as the sum of the volume of air and volume of water

FIGURE 5.28 Load and M/ EI diagrams and elastic curve for a simple beam with mispan load. The tangential deviation t of a point on the elastic curve is the distance of this point, measured in a direction perpendicular to the original position of the beam, from a tangent drawn at some other point on the elastic curve. B Mx t  t   dx (5.64) B A Equation (5.64) indicates that the tangential deviation of any point with respect to a second point on the elastic curve equals the moment about the first point of the M/EI diagram between the two points. The moment-area method for determining the deflection of beams is a technique in which Eqs. (5.63) and (5.64) are utilized. Suppose, for example, the deflection at midspan is to be computed for a beam of uniform cross section with a concentrated load at the center (Fig. 5.28). Since the deflection at midspan for this loading is the maximum for the span, the slope of the elastic curve at the center of the beam is zero; i.e., the tangent is parallel to the undeflected position of the beam. Hence, the deviation of either support from the midspan tangent is equal to the deflection at the center of the beam. Then, by the moment-area theorem [Eq. (5.64)], the deflection yc is given by the moment about either support of the area of the M/EI diagram included between an ordinate at the center of the beam and that support. yc   2 4EI 2 3 2 48EI Suppose now, the deflection y at any point D at a distance xL from the left support (Fig. 5.28) is to be determined. Referring to the sketch, we note that the distance DE from the undeflected point of D to the tangent to the elastic curve at support A is given by