*3.1.2 Structures and foundations*

The structural system option adopted in the SHS project is that of structural masonry, noting that so far priority has been given to the reinforced masonry technology with two-hole compacted earth blocks (CEBs). However, studies on the application of masonry with concrete blocks have also been carried out [22], with favourable results.

In the CEB reinforced masonry system, the blocks are laid with mortar, and consist of masonry panels with a structural function, and stiffeners where necessary (especially at the side of doorways and windows). At points predetermined by the designer, reinforcements are positioned in the holes of the blocks (and

**85**

**Figure 5.**

*Elements of the structural system of the embryo 2. Source: [23].*

*Simple Housing Solution Project: (Re) Building in Critical Situations*

embedded in the foundations), which are subsequently filled with fluid concrete (grout). As part of the CEB masonry system, there are reinforced concrete bond beams on five levels (below and above window openings and doorways, at the slab level, at the gable half-height, and perimeter of the roof gables). The structural system also has a set of frames that integrate the masonry with the purlins using the stiffener connections at the level of the contour concrete bond beams) (**Figure 5**). Considering that there are still no technical standards that address the design of structural masonry in CEB, the calculations were based on the adaptation of the former British standard BS 5628–2 (2005), which was considered adequate due to its history of success and addresses different materials. The minimum strength of the brick established by the NBR 8491 (2012) standard is 2 MPa and several tests were carried out on the materials used in the project to determine the parameters used in the structural calculation, as mentioned in Section 3.3. Wind calculations were performed according to NBR 6123 (1988). The combination of loads was made

Strip footings (with light reinforcement) under the walls were used as foundations. In order to reduce the excavation and backfilling costs, the footing installation was designed for a very shallow depth, 0.40 m. An allowable stress of

all possible soil types. Even with this conservative value, soil investigations are recommended. Since almost all types of soil investigations require some sort of costly equipment and trained crew, the DPL (dynamic probe light, ISSMFE, 1989, ISO 22476-2: 2005) was chosen for this purpose. The DPL is a simple test that employs light inexpensive equipment, and can be carried out by local personnel with simple training. The test consists of continuous driving a standard cone

500 mm drop height (**Figure 6**). The number of blows to drive the cone 10 cm (N10) must be logged. In general, the test can reach a maximum depth of 8 m [24]. The N10 value can be used as an indirect measurement of soil resistance. However, there are no reliable correlations between N10 and allowable stresses for shallow footings, as in the case of the standard penetration test (SPT). Therefore, the use of minimum values of N10 = 6 to a depth of 5 m was a conservative suggestion in

was adopted to allow the same foundation dimensions in almost

) into the soil using a 10 kg hammer with a

*DOI: http://dx.doi.org/10.5772/intechopen.94953*

according to NBR 8681 (2004).

(with a nominal base area of 10 cm<sup>2</sup>

the present application.

only 50 kN/m<sup>2</sup>

### *Simple Housing Solution Project: (Re) Building in Critical Situations DOI: http://dx.doi.org/10.5772/intechopen.94953*

*Natural Hazards - Impacts, Adjustments and Resilience*

(plus two bedrooms) and can house a family of six or less. Embryo 3 consists of vertical expansion of embryo 2 (embryo 1 plus two bedrooms) in situations with space restrictions on the building site. Embryo 4 consists of a vertical

*Expanding possibilities for residential modules from embryo 1. (a) Internal view of embryo 1 (see Video 3). (b) External view of embryo 1. (c) Vertical expansion of embryo 1 to embryo 3 (see Video 4). (d) Lateral expansion of embryo 1 to embryo 2 (see Video 5). (e) Vertical enlargement of embryo 2 to embryo 4 (see Video* 

The structural system option adopted in the SHS project is that of structural masonry, noting that so far priority has been given to the reinforced masonry technology with two-hole compacted earth blocks (CEBs). However, studies on the application of masonry with concrete blocks have also been carried out [22], with

In the CEB reinforced masonry system, the blocks are laid with mortar, and consist of masonry panels with a structural function, and stiffeners where necessary (especially at the side of doorways and windows). At points predetermined by the designer, reinforcements are positioned in the holes of the blocks (and

enlargement of embryo 2, in order to accommodate two families.

**84**

*3.1.2 Structures and foundations*

favourable results.

**Figure 4.**

*6). Source: [21].*

embedded in the foundations), which are subsequently filled with fluid concrete (grout). As part of the CEB masonry system, there are reinforced concrete bond beams on five levels (below and above window openings and doorways, at the slab level, at the gable half-height, and perimeter of the roof gables). The structural system also has a set of frames that integrate the masonry with the purlins using the stiffener connections at the level of the contour concrete bond beams) (**Figure 5**).

Considering that there are still no technical standards that address the design of structural masonry in CEB, the calculations were based on the adaptation of the former British standard BS 5628–2 (2005), which was considered adequate due to its history of success and addresses different materials. The minimum strength of the brick established by the NBR 8491 (2012) standard is 2 MPa and several tests were carried out on the materials used in the project to determine the parameters used in the structural calculation, as mentioned in Section 3.3. Wind calculations were performed according to NBR 6123 (1988). The combination of loads was made according to NBR 8681 (2004).

Strip footings (with light reinforcement) under the walls were used as foundations. In order to reduce the excavation and backfilling costs, the footing installation was designed for a very shallow depth, 0.40 m. An allowable stress of only 50 kN/m<sup>2</sup> was adopted to allow the same foundation dimensions in almost all possible soil types. Even with this conservative value, soil investigations are recommended. Since almost all types of soil investigations require some sort of costly equipment and trained crew, the DPL (dynamic probe light, ISSMFE, 1989, ISO 22476-2: 2005) was chosen for this purpose. The DPL is a simple test that employs light inexpensive equipment, and can be carried out by local personnel with simple training. The test consists of continuous driving a standard cone (with a nominal base area of 10 cm<sup>2</sup> ) into the soil using a 10 kg hammer with a 500 mm drop height (**Figure 6**). The number of blows to drive the cone 10 cm (N10) must be logged. In general, the test can reach a maximum depth of 8 m [24]. The N10 value can be used as an indirect measurement of soil resistance. However, there are no reliable correlations between N10 and allowable stresses for shallow footings, as in the case of the standard penetration test (SPT). Therefore, the use of minimum values of N10 = 6 to a depth of 5 m was a conservative suggestion in the present application.

**Figure 5.** *Elements of the structural system of the embryo 2. Source: [23].*

**87**

(**Figure 7b**).

**Figure 7.**

such as washing floors.

hood has to be built (**Figure 9**).

*3.1.4 Urban design*

*Simple Housing Solution Project: (Re) Building in Critical Situations*

an individual sewage treatment system using a combined septic tank and sinkhole

*and laundry area with a primary treatment system. Source: [26].*

*(a) Internal distribution system - bathroom with apparent pipes. (b) a waste collection system in the bathroom* 

Concerning the rainwater drainage systems, a simplified solution was proposed. The rainwater flows from the roof to catch basins and then to the public storm water system, whenever applicable. As an alternative, a rainwater harvesting system can be installed using rain barrels (**Figure 8**). In this case, it is necessary to install gutters, roof drains and downspouts connected with a rain diverter to the rain barrel. These barrels would accumulate the rainwater, reserving it for less exciting use,

Different typologies of the urban subdivision were conceived for a pilot project considering at least 100 homes in embryo 2, including the necessary community facilities (schools, health centres and public squares) to serve the expected population. For each 100-home model, simple replication logic was applied to extend the project in case of more significant needs, for example, when an entire neighbour-

*DOI: http://dx.doi.org/10.5772/intechopen.94953*

**Figure 6.** *DPL (a) equipment; (b) testing. Source: [25].*
