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Hi all Steemian,

I am sharing with you information about technology in civil engineering. The choice of a type of constructions in development building is very important. In building construction, there are two structures- bottom structure and up structure. Determining the type of foundation has to be precise cause it endures all load both living and non-living things loads. The Foundation of spider web construction is one of kind swallow foundation that creates by Indonesian People. 

History spider web construction

This system was found in 1976 by Ir. Ryantory and Ir. Sucipto when they had to find the failures at bottom floor in any projects which used deep foundation as well as shallow foundation. At that time, they both studied in Surabaya Institute of Technology. As the result, they found the construction of deep foundation remain stable, however, due to the dropping of non-structure on the floor it caused arise crack on the floor, hallway and wall.

For half-high rise building with shallow foundation, digression often occurred but floor repairment needs much cost. For the reasons,   Ryantori and Soetjipto had been thinking to create new foundation system, that could make all bottom floor function as well as foundation which became unity of rigid and could adjust with all soil condition with economical cost. Having various trials and long discussion, eventually a new foundation of construction found which soon-named spider web construction.

The understanding of spider web contrsuction

![](https://steemitimages.com/DQmQ8R8HMKnYHudEnnCVSse1NVrgcbJS1h1VsbQw3gPnEDg/image.png)

 
Spider web construction is a system of bottom-building construction that combines between strength of concrete and soil improvement system that is used in the area with soil bearing capacity around between 0.15-0.4 Kg/ Cm2. With a shape of construction's system like that, then SWC can be described as a dense layer of coral with strength and capacity.

The Foundation of spider web system is a bottom foundation of conventional which is sturdy and economical. The strength of concrete is a foundation system of flat plate which doing erect ribs high flat with soil improvement system between ribs. This combination caused availability mutual cooperation each other, so that form a foundation. 

![](https://steemitimages.com/DQmYSUA88J2VKtbUfHKcyHAaT4nQSXrmGUoQ7ZAvpWZ3qPM/image.png)

It was named web spider construction because steel reinforcement formed spider web. Its feature attracts each other and monolith which means in one unity. The construction plate designed for multifunction, for septic tank, reservoir tub, floor, stair foundation, lintel or practical column and rib’s wall. SWC does function as spreaders tension or forces as on columns. Filler sand and soil are compacted which functions as strangulate ribs.

in accordance with the definition so SWC consists of two-part is :
1.	Concrete construction
2.	Soil improvement/sand


![Pondasi sarang Laba2.png](https://steemitimages.com/DQmZGNWcqv28ZEEb8GZrffXr1apvpoDq7DxEXsaoCTDkwdg/Pondasi%20sarang%20Laba2.png)

Note :
1a . flat reinforced concrete plates
1b - construction rib
1c – settlement rib
1d – divisor rib
2a -  sand dump is compacted
2b – soil dump is compacted
2c – Base course is compacted


According to the workshop  held up in Bandung  at half 2004 years ago by Puslitbang Depkimpraswil in present by  earthquake expert and geologist, conclude excesses the foundation of SWC are as follows :
1.	SWC have better stiffness with use minimize materials more than raft foundation.
2.	SWC has the ability to minimize the differential settlement and reduce irregular differential settlement when compared with the raft foundation.
3.	SWC  able to make the soil become part of the foundation structure because the compaction process will negate the effect of folding or lateral buckling on the rib.
4.	SWC has the potential to be used as a foundation for low-rise buildings (2 floors) built on soft soils considering the total possible settlement.
5.	An implementation does not use heavy equipment and does not interfere with the environment so it is suitable to be applied both in densely populated locations and in remote areas.
6.	SWC able to save the use of steel reinforcement or concrete.
7.	The required execution time is relatively faster and can be implemented labour-intensive.
8.	SWC is more economical than conventional foundations of rafts or piles, especially with deep foundations, making them suitable for developing countries because they are cheap, labour-intensive and simple.

Privileges Of Construction Systems And Forms Of Profit Spider web

SWC  foundation features can be seen from the technical aspect, economical and from implementation aspect.
From the above descriptions can be summarized in the following points:
I. Technical Aspects
a) Firming on ribs and plates is sufficient with minimum minimization.
b) Resistance to high differential settlement due to the working stress of the load is already uniform in the supporting soil layer. This is also due to the preparation of the rib in such a way that it divides the extent of the foundation of SWS into plots each of not more than 200 m2 so that the foundation of SWC has a high resistance to differential settlement.
c) Total settlements become smaller due to increased density in the supporting soil layer under SWC due to the effect of effective compaction on the soil layer of improvement in the KSLL as well as the working of the shear stresses on the outermost rib of the SWC.
d) The resistance to earthquakes is higher because SWC is a monolithic and rigid construction.
e) Land improvement within SWC has permanent stability due to protection from SWC rib-rib
f) SWC can also replace the function of various constructions other than its function as a foundation, among others:
 -  As the foundation of columns, walls, and stairs
 - As a sloof / confinement blocks
 - As a floor plate construction (base) 
 - Urugan / soil improvement with soil compaction
 - Retaining wall under the floor
 - Construction of safety against the stability (density) of soil improvement under the floor
 - Couples and plastering of the wall beneath the ground floor
 - Column below ground floor level
 - Septic tank and recharge
 - Tub reservoir (if required)
 The KSLL widening of ground floor area can be arranged in such a way that it can be utilized as  a sidewalk or parking lot.

II. Implementation System
a) Due to the simplest form and construction system, it is possible to be implemented with simple equipment and does not require high skills.
b) Implementation is faster than other foundation systems.

III. Economical
Compared with other foundation systems, KSLL can reduce the cost considerably big. Generally obtained savings of:
 - 30% for 3 - 8-storey buildings  +/- a)
 - 20% for 2-storey building +/- b)
 - 30%  for The warehouse buildings of first class +/- c)


Source :

1. https://filbertreginald.wordpress.com/2010/12/07/pondasi-ksll-karya-anak-bangsa-indonesia/
2. http://blog-oong.blogspot.co.id/2011/10/pondasi-Sarang-laba-laba.html
3. http://harianproyek.blogspot.co.id/2015/04/ir-soetjipto-ir-ryantori-penemu.html
4. http://pratamaclaudio.blogspot.co.id/2016/10/pondasi-sarang-laba-laba.html
5. http://harianproyek.blogspot.co.id/2015/04/ir-soetjipto-ir-ryantori-penemu.html
6.https://www.google.co.id/urlsa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwiZl7LZ_TYAhVJLpQKHQ21BYUQFggoMAA&url=http%3A%2F%2Feprints.undip.ac.id%2F34240%2F1%2F1771.pdf&usg=AOvVaw0SG81t27C43h1QWEPOE1wt



Best Regards

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