# PARAM VISIONS

All about civil construction knowledge- PARAM VISIONS

### What is rubble (boulder) soling? - their purpose & thumb rules in soling calculations.

#### 1. What is rubble soling?

Rubble soling is the procedure of laying hard stones of required specifications adjacent to one another, with minimal voids in between them. The gaps are filled with stone chips or moorum to firmly pack the soling as required.

Before proceeding further, go through the article ðŸ‘‡

to understand the soling concept clearly.

#### 2. Why do we provide rubble soling in the construction works?

We provide rubble soling for the following 3 main purposes.

a. To provide a hard & firm base or sub-base for the upper structural layers.

b. To increase the bearing capacity of the soil or strata.

c. To provide a leveled base above the undulated strata for PCC or any such works.

#### 3. What are the thumb rules used in the rate analysis of rubble soling works?

In the rubble soling work, we use stones that are irregular & unequal in their sizes. So, we cannot do an accurate estimate of the materials required in doing rubble soling work.

As mentioned below, certain thumb rules are followed in the estimation & rate analysis of rubble soling works.

1. The loose stone required for the rubble soling is 1.25 times the total volume of the work.

Suppose, if the volume of the rubble soling  = 10 cu ft.

The volume of the rubble or stone procured for the soling work = 1.25 × 10 cu ft. = 12.5 cu ft.

2. The volume of the moorum required for the soling work will be 15% of the total volume of the rubble stone.

Suppose, if the volume of the rubble = 10 cu ft.

The required vol. of the moorum = [15 × 10 cu ft.÷ 100] = 1.5 cu ft.

#### 4. What are the factors that affect the required volume of the materials in a rubble soling work?

Various factors that affect the stone & moorum vol. in the soling work are,

1.  The depth or thickness of soling.

2. Shape & size of the rubble stone.

3.  Degree of soling compaction & type of compactor used.

4. Volume of stone chips used.

5. Degree of neatness in hammering & packing the stone.

6. Surface finish, texture & type of stone used.

7. Wastage of materials.

Depending upon the above factors, the required loose volume of the rubble stone varies from 15% to 30% of the total vol. of the soling work.

Similarly, the required volume of moorum ranges from 10% to 20% of the total rubble stone volume.

We consider the average of the consumed material to bring the estimation or rate analysis, nearer to accuracy.