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The following are collection reviews from the MCS team members for your reference. Shall there be any query in regards to the review(s), kindly contact the team member(s) for clarification.

Sample of Geology and Pedology Report

posted Sep 8, 2019, 6:51 AM by jeffery jim

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** This kind of report usually forms the introduction before full geotechnical report and analyses. It also forms fundamental points which will be disseminated in various arguments or validations or parsimonious references; suitable when rendering contexts of discussion and summation.***

Based on Soil Map of Sabah, the site is located within an area which consists of two types of main soil association which are; Tuaran and Kinabatangan where both soil types are of alluvium parental material. Nevertheless, the main component of the pedosphere would most likely consist of soil units from the Tuaran soil association. The location of the water intake sits on the meandering belt of the river and the treatment plant is likely sitting on the foot of terraces or undulating land which fits the Brantian soil association.

Fluvisol indicates that part of the meandering belt consist of stratified fluviatile, marine and lacustrine sediments while Cambisol significantly render a quite moderately developed soil with little or no profile differentiation, and Gleysols indicates that groundwater can be very shallow and have excessive wetness, saturated and stagnant at the top 50mm of the soil strata.

At the higher terrace, Acrisols consist of acidic low-activity clays with low base status and Podzols is related to subsoil accumulation of humus and/or oxides (Al or Fe ions and chemistry). These classifications under WRB Reference Soil Groups (RGSs) shall be complimentary to information acquired from site exploration, boreholes and relevant lab test in accordance to BS5930 and BS1377.

The main concern with Gleysols would be the ability to reduce oxides to soluble and transport it within the strata and a huge concern when it comes to redoximorphic features. This redoximorphic is coupled with oximorphic which alternative reducing and oxidizing conditions. This is consistent with the finding from some boreholes before fragmental stratum with soil of greyish/bluish color.

Fluvisols is equally harmful since most Fluvisols are closely related with acid sulphate soil if there is the presence of Pyrite.

Beaufort (Sg. Padas) Flood Modelling

posted Sep 8, 2019, 6:49 AM by jeffery jim

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I am about to conclude my conference paper on Beaufort flood modelling. It was a study I conducted close to zero-cent cost (except for my time) and yield a satisfactory result. The flood model calibration is quite close to the actual scenario without any bathymetric survey and so on. The flood level calibration is off by 0.07m or 70mm, so I can assume it is significantly accurate considering the model involves closed to 9,000 km².

The call for paper took place a month ago and this is not my thesis, it is just a second paper for my second proceeding within a period of 5 days with two different organizers. I am not here to seduce you to join these conferences since both are closed and were opened mainly for specialist within the academia world, government bodies/agencies, NGOs and the industry.

What I want to share here is the outcome during storm event for Padas River, mainly at the Beaufort floodplain. Without proper mitigations, for upstream storm case (heavy precipitation at Ulu Padas and Catchment), you will see the rise of water between 4.07m (4m at Kg. Cina and Beaufort town - as reported by DID based on 2014 flood) for 2 Years ARI, 4.78m for 50 Years ARI and 5.64m for 100 Years ARI.

It would be even worst if both catchment areas (8,800km²) and flood plain (224.65km² based on spatial water movement) experienced extreme storm. We are looking at maximum depth of 8.65m during 2 Years ARI, 11.26m for 50 Years ARI and 11.20m for 100 Years ARI although the mean would be between 6m to 8m for all cases. This has yet to include other determinants such as climate change, dam spillway discharge and inefficiency of hydraulic structures.

I just hope all the agencies, policy proponents and those who are responsible would listen to me attentively so that no life is at stake.

Slope Failure at Tanjung Bungah, Penang

posted Sep 8, 2019, 6:48 AM by jeffery jim

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I just got a copy of the Commission of Enquiry Report which highlighted the culprit of the whole incident, the Principal engineer of KAA, Ir. Khoo Koon Tai. He committed gross negligence and could have remedied the problem for more than ten (10) occasions but he prefer to hang the skeleton in his closet.

First, what he did is not value engineering. It is the opposite of value engineering for any cost saving design and exercise. After 4 landslip events, he did nothing. What really surprised me is his inability to call for interim monitoring before committing to any design change and slope rehabilitation. Leave alone the other basic engineering practice which he deliberately ignored.

Dumbfounded by the whole case, I wonder if he have the access to knowledge for monitoring and supervision purposes. I think he lacked of understanding when it comes to engineering and design philosophy. When encountered by extreme case or unknown, it is best to design assisted by series of testing. That is the main rule which is clearly mentioned in Eurocode.

To be frank this site is relatively small or puny in comparison to some of the road construction sites. With four slopes and three berms, it is considered as a minor slope in comparison to some road project slopes which reached up to eight to twelve berms. It is deemed to be an everyday slope for most of us.

After the second landslip and the deviation from the conceptual design, he should have halted all works and review the slope FOS. It is true that what attained during site investigation may varies, it is also a proper practice by discharging his duty and liability with simple geotechnical instrumentation such as piezometer and inclinometer.

These instruments will assist in checking the ground water table and also soil movement which allow one to understand the actual scenario of the hydrostatic pressure and the strata movement. When inclinometer ratio is more than 0.2, it is time to stop work at the affected or adjacent areas.

Another thing which rarely good engineers or clerks-of-work are able to pick up is wet or saturated water condition at the top slope and stress crack lines or fissures.This indicates the matured slip circle formation where cohesion and internal angle of friction have lapse and the stability is now critically dependence on the self-weight and counterbalance at the slope toe. By rule of thumb, if you find stress fissure at the top slope, the FOS is around 1.1 to 1.2 where JKR Guideline for slopes require around 2.0-2.5 for different criteria which forms the global stability requirements.

The top slope fissure usually indicates Acrisols (low base and plasticity clay) soil is saturated with water. That the easiest tale-tell sign that one may need in order to build a conclusive preliminary condition of a slope. It means the load is more than the soil's ability to hold on through the internal angle of friction and cohesion.

In case fissures turned to crack lines which are more than 1 or 2mm wide, the first thing to do is to order for a counterbalance measure to be placed at the slope toe (rock-filled gabions) in order to contain the slip. Second, horizontal drain should be installed with tarpaulin lining for the swale-like earth drain instead of deep surface drains for draining ground water and reduced water flow net which subsequently stabilize the slope by reinstating the internal angle of friction for soil. Lining is helpful against introducing or recharging the ground water due to infiltration and due to surface runoff during storm event.

Once mitigation measure have taken place, it is time to install piezometer and inclinometer at critical areas for monitoring. No earthwork is allowed 10m to 15m away from this slope. After a period of 60 to 90 days, sacrificial soilnail or rock bolt test is allowed.

What ductility class structure do we really need?

posted Aug 10, 2019, 9:16 AM by jeffery jim   [ updated Aug 10, 2019, 9:38 AM ]

Back in 2015, the largest earthquake with magnitude of 6.0 Richter scale hit Kundasang, Ranau. This incident severely affect many of those residing at surrounding areas with multiple (almost or more than hundred shock waves) after killing many on its initial tremor early morning.

One of the most structure that have been investigated ever since by many professionals and academicians is the teachers flat/quarters at SMK Ranau. I did use this as a case study during one of my talk when training Sabah State JKR personnel. It is a classic case study.

After almost two or three years after my first article about this when i try to demystify the issue of the safety of the design for this structure by conducting finite element analysis, i found another conference proceeding paper which discusses similar subject but a little bit bemused and at the same time amused with their claim.

Nevertheless, i shall not discuss their finding since there are gaps between professionals and academicians when talking about dilapidation or the criteria or criterion of what defined as lapse serviceability state limit. The outcome from my calculation to their calculation differs, similarly with outcomes for diagnosis and prognosis. One particular claim that which need to be cleared here is the purported claim in this paper about the column joint crack. Desktop studies shows otherwise, where the crack is actually construction joint; perpendicular to the column direction.

Now, i am not interested with their finding on this but i am thankful that some of the data in regards to the t value or time step value which projected the excitation value. The highest value is 0.11m/s2 or 0.12g from this paper. The Seismic Hazard Map in Malaysian Annex indicate the value of around 0.17g.

From Soil of Sabah Map, SMK Ranau is situated in between Pinosuk and Brantian Soil. In this case it sits on a plateau with colluvium. Colluvium is a heterogeneous mix of sediment which increases the S multiplication factor increases from 1.3 to 1.8 for class C soil. Hence, it is appropriate to say the peak ground acceleration reacting on the structure have increased to 0.216g.

Despite of its soft story at the ground floor, the structure hardly lapse its designed ultimate limit state and one have to accept that the performance without increasing the ductility class to DCM or DCH will still be robust enough to restrain the structure by force instead of energy. Unlike recommendation made in Eurocode where 'ag' value of more than 0.1G requires special design, we can also accept that the DCL designed is robust enough to withstand magnitude 6.0 which is situated 6km away.

Therefore, we can generally accept that DCL based on Eurocode 2 or BS 8110 or BS 8103 can survived such magnitude although the damage limitation percentage may increased. It is also reasonable to increase the design from DCL to DCH or DCM to reduce the damage limitation percentage to a mere 10%.

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DBP Structural Integrity

posted Aug 10, 2019, 9:15 AM by jeffery jim

Isn't rehabilitation and repair possible? Yes, it is possible but it is also an obstinate thing to do. You definitely can change but all the temporary works, false works, form works and etc will be extremely high for preliminaries and generals section. Now, the other problem would be, where can the staging or platform for this rehabilitation work be secured to? None of the structure is sound for a safe working platform connection, shoring or other works.

Now, clamps for typical tubular scaffolding system need at least 2 to 3 up to 6kN. With such delamination or dilapidation or worst, loss of surface; where can staging components secured to?

Talking about galvanization, oxidation, rusting, corrosion or what so ever you want to call it, it is no longer feasible to do jacketing or retrofitting.

1. Jacketing increases weight and change the polarization of the ion movement in a rust or galvanization circuit. Introduction of steel jacket will change the existing point from anode to cathode which will aggravate areas which was not corroded earlier. This will affect all since most of the connection plates shall be replaced and this is the major contributor to induced or reverse polarization of the oxidation circuit.

2. The introduction of CFRP is great since it is lightweight but is not holistic since this polymer will deteriorate over time after exposed elements and vibration. CFRP usually can last or effective for only 5 years. This mean routine checks and periodical checks are required after reinstatement. That is another cost which people failed to see. There is difference when talking about physical construction cost and economics of such works.

3. Change of material and fittings. Changes of material may not be deemed as feasible since all material including paint have its own property especially their moduli value. I don't subscribe to the simpleton argument. It can be feasible when under static condition or at rest. Nevertheless, under active condition or dynamic, that is another issue. Changes in barometric pressure does change the wind load and movement which will induce the structure to moments. Propagation of force and moment due to mentioned action will give different outcome for old retrofitted structure and newly replaced structure. Lost of mass for any steel structure will create deficit in their capacity and ability.

In short, structural rehabilitation or repair only suffice intended performance when the structure does not lapse its ultimate state limit. In this case, people surrounding the building can be considered as blessed since this structure haven't disintegrated, fall and impale some of you. Count your blessing and Godspeed!


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Contract - Extension of Time (EOT) and Loss and Expense (L&E)

posted Jul 30, 2019, 7:58 AM by jeffery jim   [ updated Jul 30, 2019, 8:04 AM ]

It has been a while since I played contractual game and most of these issues are about to be deleted from my memory. I will only use these two clauses for some of my tactical planning work for exclusive clients. So here is a short write-up about both clauses in JKR Form 203 and Form 203A.

First of all, before we enter into the agreement, all parties should understand the concept of "True Intent" which binds the whole covenant as mutually explanatory for all the avoidance of discrepancies and divergence which may frustrates the original contract. The lack of Instructions by Client is not deem valid if the Contractor acted badly by sitting on the issue or showed negligence.

Two, the contract always end with time where time is of the essence of any agreement and time should take precedence for instruction(s) and reason(s).

Contractual game is an interesting game but one have to be smart and tactical enough when playing it. Showcasing outright ill intention and deep-rooted prejudice will not bring the Contractor anything good or even relieve the Contractor from his duties and discharging his obligations. In case Contractors forgot about their main duty, it would be to indemnify the Client at all time, which mean the Contractor shall be a partner and forefront of the Project in a professional manner.

Now, the case is about a Contractor who is trying to win loss and expense after granted extension of time by the client. Can the Contractor be paid for the loss of his time? It depends.

Loss and expense can only be granted if it fits certain caveats highlighted in the following paragraphs.

a) The main obligation the Contractor should perform is to notify through writing in event where certain factor(s) or event(s) (usually in the CPM) which lead to unforeseen possible delays to justify their EOT submission as well as THE HIGHLIGHT OF INCURRED COST DURING THE DELAY and to DISPLAY POSSIBLE DELAY TIME AND COST BY DAYS IN A WORK PROGRAM. The Contractor also should demonstrate the cost of delays through Schedule of Rate and where needed, to breakdown rate or price or cost.

b) If evidence cannot be produced within one month, it is good enough that the Contractor just send in a notice and subsequently furnish with supporting documents and dossiers as mentioned in the paragraph above. Contractor should also notify the Client on their intention for EOT only or both EOT and L&E. Failure to this may disqualify the Contractor from claiming incurred cost under L&E. Similar to EOT, Contractor should notify the Client in one calendar month. Final submission for L&E can be done after the completion of the project when finalizing the Final Account.

c) L&E can only be considered due to the followings;-
(i) Suspension of Works by the Client unless the Contractor failed to protect, store and secure works from deterioration; or to take necessary action to mitigate expenses incurred.
(ii) The Contractor discharged his obligation during a dispute due to neighboring owners - as long it is not the fault of himself, sub-contractor(s) or NSC.
(iii) Delay of Instructions provided that is not issued due to any act, negligence or default by the Contractor and co. Apart from that if Instruction was relayed late or not received in due time.
(iv) Delays in unavoidable or unforeseen or not catered for due to the delays by third party engaged by the Client.

It is dire important that the Contractor should stand true to the original intention of the Contract and properly relay notice(s) in order to be entitled for claims, both EOT and L&E.

Relationship; SS of FF?

posted Jul 20, 2019, 7:57 AM by jeffery jim

Question:

You are tasked to designate the relationship between embankment fill and spot turfing at area with land compensation issues. Choose the appropriate relationship and justify why.
(10 points)


Answer:

The key answer and determination of type of relationship depends on the plausible or possible complication during construction and the contractual issue bound to it for EOT purposes.

When encounter possible delays caused by a predecessor, always highlight it and let other subsequent activities which are related tied to it be consequential. In this case, instead of using SS, it is best to use FF relationship. If you need additional 14 days for turfing to complete after embankment fill (it is a need to complete or cover the cut or fill area), thus the relationship shall be FF+14d or FF+10d depending on your calendar.

Here it highlights two possible delays that affect both activities. One - land inquisition and the delay in starting earthwork. Two - land inquisition and possible additional land inquisition for ROW for slope stability works.When work on FF, it highlights causal-effect as it also maintains the CPM which includes both issues.

In this case, it is clear that either one of these actual create impact on the generated schedule updates.Typically, this would be SS relationship for greenfield but not at areas with complication.This will explain easily rather than to show splits. It somehow help your client to understand the event and award you additional time

Landslide and Quake Dam

posted Jul 20, 2019, 7:55 AM by jeffery jim

Not many people understood why about this phenomena which keep some people scratching their head when a sudden flood occurred during a sunny day. It happened during the great earthquake which affect areas around Ranau and Kota Belud as well as triggered the largest and devastating outcome after Greg Storm passed through Keningau.

Landslide and quake dam is the outcome of built up which creates natural dam from natural flocculation and sediment load due to various erosion (both banks and surface) and transportation types.

The increasing height of debris and sediment create artificial wall(s) which retain and contain water until the point where the hydraulic pressure is greater than the wall (cohesion or friction angle or even combined) and thus cause the wall to breach and lead to overflow.

This sudden overflow and the magnitude of the flow depend on the type of breach or failure at the upstream and the downstream is at the mercy of the river capacity and amplification due to topography. Only spatial distribution and luck will give you a lucky escape.

If you live around such area, you are one Hail Mary prayer away from being safe due to evaporation and possible infiltration. Else, with impermeable clay - you can start with John 3:16.


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Honeycomb Repair

posted Jul 20, 2019, 7:54 AM by jeffery jim

The second query for this morning is in regards to honeycomb repair - coming from Singapore. A Professional Engineer from Singapore requested the contractor to rectify concrete structure with honeycomb post concreting. Repair work is fairly or relatively easy but it comes with a set of questions like how durable, bonding issues and miscellaneous.

The bonding between freshly repaired grout or concrete and the existing concrete infill and cover can be established by using bonding agent instead of using just cement slurry. There is a caveat to this context. The surface to receive both bonding agent and the fresh grout or concrete should have jagged surface and free from feather edge. The application should be based on MDS provided by manufacturer. If bonding agent does not suffice the requirement or the so-called Supervision Officer, you can include J-dowel for additional grip. But that is taking it to another level which is clearly needless. Concrete is intended for situation under compression and not the rest, therefore the issue with concrete strains is less likely to cause issues when under other stresses. Second worthless justification one can do is to do pull out test for the bonding agent to ensure it is complied with what is reported in the MDS.

After making repair for the affected structure, the integrity of the structure can be tested by using Ultrasonic pulse to ensure there is no honeycomb or void after repair. As for the concrete compressive strength, a normal sampling during batching is good enough to give clear indication of the characteristic strength achieved by the fresh concrete or grout.


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Aggressive Soil - Steel and Concrete

posted Jul 20, 2019, 7:54 AM by jeffery jim

There is this query coming in about the use of DI pipe instead of MSCL pipe because of aggressive ground. Nevertheless, the site have to aggressive ground except for remote case where there is a lower pH reading close to a drain, garage and recycle collection center. After dismantling these structures, the source of such aggressive substance will no longer affect the underground pipe since by default, the original ground is not filled with possible pyrite. The other possibility is possible runoff from other areas contaminated with acidic compound(s) or substance(s).

Pyrite is a byproduct from certain earth with acid sulfate composition which is mainly available around the coast line in Sabah and at times, it is reported in SI report. Nevertheless, for overall justification, the Sabah Soil Map is the best resource to have indicative and general for the soil condition.

But in case there is the brownfield area where there is possibility of extreme cases with highly aggressive ground, it is best to refer to BRE SP1 as a guideline for substructure or foundation design and as a basis to make projected calculation on corrosion based on NACE requirements.

Between concrete and steel, the concrete substructure would be worrisome when the concrete is below grade G40 which is less robust since most of these grades have higher than 0.40 free water cement ratio. This induces volatile and aggressive substance to penetrate into the concrete by aggravating the concrete cover and reach the reinforcement bar. Pitting will cause loss of surface and subsequently reduced the "As" of the designated concrete structural member(s). Hence this will reduce the capacity of the foundation.


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