Improving Earthquake Resistance of Small Buildings

The earthquake resistance of small buildings may be increased by taking some precautions and measures in site selections, building planning and constructions as explained below:

1.Site Selection

应避免建筑结构

(a) Near unstable embankments

(b) On sloping ground with columns of different heights

(c) Flood affected areas

(d）在某些部分和某些部分的一些部分和土壤中具有明显的不连续性的底层。

2.建筑规划

对称的计划和unsymmetrica相比更安全l plans. Hence go for square or rectangular plans rather than L, E, H, T shaped. Rectangular plans should not have length more than twice the width.

3.Foundations

Width of foundation should not be less than 750 mm for single storey building and not less than 900 mm for storeyed buildings. Depth of foundation should not be less than 1.0 m for soft soil and 0.45 m for rocky ground. Before foundation is laid remove all loose materials including water from the trench and compact the bottom. After foundation is laid, back-fill the foundation properly and compact.

4.Masonry

如果是石头砌体

• Place each stone flat on its broadest face.
• Place length of stones into the thickness of wall to ensure interlocking inside and outside faces of the wall.
• Fill the voids using small chips of the stones with minimum possible mortar.
• Break the stone to make it angular so that it has no rounded face.
• At every 600 to 750 mm distance use through stones.

如果是砖砌体

• Use properly burnt bricks only.
• Place bricks with its groove mark facing up to ensure better bond with next course.

在混凝土块的情况下

• Place rough faces towards top and bottom to get good bond.
• Blocks should be strong.
• Brush the top and bottom faces before laying.

通常应避免超过450毫米的墙壁。墙的长度应限制在6米。交叉墙使砖石变得更加强大。最好沿着主墙壁构建隔断墙壁交互墙壁。

5.门和窗户开口

• Walls with too many doors and windows close to each other collapse early.
• Windows should be kept at same level.
• The total width of all openings in wall should not exceed 1/3rd the length of wall.
• Doors should not be placed at the end of the wall. They should be at least at 500 mm from the cross wall.
• Clear width between two openings should not be less than 600 mm.

6。屋顶

• 在坡度倾斜的屋顶，跨度大于6米，使用桁架而不是椽子。
• Building with 4 sided sloping roof is stronger than the one with two sided sloping, since gable walls collapse early.

7。Chejjas

Restrict chejja or balcony projections to 0.9 m. For larger projections use beams and columns.

8。栏杆

Masonry parapet wall can collapse easily. It is better to build parapet with bricks up to 300 mm followed by iron railings.

9.具体的and Mortar

Use river sand for making mortar and concrete. It should be sieved to remove pebbles. Silt should be removed by holding it against wind. Coarse aggregates of size more than 30 mm should not be used. Aggregates should be well graded and angular. Before adding water, cement and aggregates should be dry mixed thoroughly.

10。Bands

The following R.C. bands should be provided

(a）底座乐队

(b) Lintel band

(c) Roof band

(d）山墙乐队。

For making R.C. bands minimum thickness is 75 mm and at least two bars of 8 mm diameters are required. They should be tied with steel limbs of 6 mm diameter at 150 mm spacing.

如果壁尺寸很大，也可以提供对角线和垂直带。

11.Retrofitting

Retrofitting means preparing a structure in a scientific manner so that all elements of a building act as an integral unit.

它通常是实现建筑物安全的最经济和最快的方式。以下是改装的一些方法：

• Anchor roof truss to walls with brackets.
• Provide bracings at the level of purlins and bottom chord members of trusses.
• 通过在山墙墙上插入倾斜带，加强山墙墙。
• Strengthen corners with seismic belts.
• Anchor floor joists to walls with brackets.
• Improve storey connections by providing vertical reinforcement.
• 通过在内部和外部的垂直加强件提供垂直加强件，诱导拉伸强度抵抗壁的垂直弯曲。
• Encase wall openings with reinforcements.